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Magnolia The Journal of the Magnolia Society International Volume 46 Issue No. 90 Fall/Winter 2011


Magnolia the Journal of the Magnolia Society International

Editor Cheryl Doyle Kearns 102 Colonial Drive Youngsville, NC 27596 919.556.6429 cherylkea1017@yahoo.com Page Layout and Design Aaron Schetttler Raleigh, NC schettleraaron@gmail.com Scientific Advisor Richard B. Figlar Pickens, SC magnolia@magnoliaceae.org

Contents

2011 Gresham Awards presented......................................................................... 1 The Magnolia collection at the JC Raulston Arboretum at NC State University.................. 4 Asiatic Magnolias and the UBC Botanical Garden.................................................... 8 A comprehensive evaluation of yellow-flowering Magnolias....................................... 13 Ploidy level, genome size, and the music of Magnolias ........................................... 30 Exploring in Vietnam.......................................................................................... 52 New cultivar registrations 2010-2011.................................................................. 58 Front Cover: Pink-flowered form of M. delavayi, JC Raulston Arboretum (photo by Mark Weathington) Back cover: Vance Hooper's award-winning M. 'Genie' (M. 'Sweet Simplicity' x M. liliiflora 'Nigra') x (M. 'Sweet Simplicity' x M. 'Black Tulip') (photo by Vance Hooper) Inside: All photographs by respective authors unless otherwise noted. MAGNOLIA, Journal of the Magnolia Society International (ISSN 0738-3053) is published two times a year by the Magnolia Society International, Inc., a not-for-profit society, as a service to its members. Address inquiries about membership and requests for copies of the bylaws to the secretary: Beth Edward, 3000 Henneberry Road, Jamesville, NY 13078, USA. Dues payments, orders for back issues of this journal, payment or inquiries concerning advertisements, and orders for publications should be addressed to the treasurer: Larry Langford, 518 Parker Street, Gibson, TN 38338, USA. Editorial contributions and inquiries about publishing articles and requirements for manuscripts, art work, or photographs for publication should be addressed to the editor. Visit the Web site: www.magnoliasociety.org


Magnolia

Issue 90

2011 Gresham Awards presented

The D. Todd Gresham Award was established in 1981 in order to recognize individuals who have made extraordinary contributions to the development, improved culture, increased knowledge and promotion of magnolias, or who have contributed outstanding service to the Magnolia Society. Lola Koerting was honored at the Magnolia Society’s banquet dinner on May 7 and Steve Spongberg was honored on May 10 during a separate ceremony which took place at the Stephen A. Spongberg Library at Polly Hill Arboretum.  Dick Figlar, Awards and Honors Chairman, made the following presentations at those ceremonies.

Lola Koerting

The story of tonight’s award recipient begins at the 1977 annual meeting of Magnolia Society at Washington, DC. I was at that meeting (it was my first) as were a few others here tonight, including Gordon Hagen, Elliott Jessen and Harry Heineman. During the Friday Awards Committee Chairman Dick Figlar (L) and MSI night presentations, a President Andrew Bunting (R) with Gresham Award recipient young and enthusiastic Lola Koerting. (photo by Anita Figlar) Plant Researcher from Brooklyn Botanic Garden (BBG) took to the podium with a slide carousel and proceeded to show to the Magnolia Society – and the horticulture world – something that had never been seen before: slide after slide of yellow-flowered precocious magnolias – the first ever hybrids between M. acuminata and M. denudata. The entire audience was astonished, energized and everything in between. Even the normally demure Joe McDaniel later referred to these photographs as “an arresting sight” in his write-up of the meeting. By now, you all know we are talking about Lola Koerting. During that time and in the years that followed, Lola went on to energize and invigorate the magnolia breeding program at the BBG’s Kitchawan Research station near Ossining, NY. Not only an accomplished plant scientist and magnolia breeder herself, Lola’s sheer enthusiasm and passion for her work served as a catalyst for action within a bureaucratic - sometimes slow-moving - BBG organization. Thus, largely as a result of her ef1


Magnolia forts, at least six important magnolias were introduced: ‘Elizabeth’ (1977), ‘Yellow Bird’ (1981), ‘Hattie Carthan’ (1984), ‘Marillyn’ (1989), ‘Lois’ (1998), and ‘Judy Zuk’ (2007). More importantly, Lola’s influence on magnolia breeding went far beyond the BBG. That the notoriously “non-showy flowered” M. acuminata could successfully be used to extend the hardiness and color ranges of existing showy magnolias represented a major paradigm shift in magnolia development. Contemporary magnolia breeders of that time, Joe McDaniel, Phil Savage, David Leach and others, quickly began incorporating Magnolia acuminata into their own breeding programs. Later, August Kehr, Frank Galyon, Dennis Ledvina and others would use those early hybrids as parents in more complex crosses, resulting in second generation hybrids like ‘Daybreak’ (from M. ×brooklynensis and a Gresham hybrid), and ‘Blushing Belle’ (from ‘Yellowbird’ and ‘Caerhays Belle’). As a result of all this, during a time when public interest in other woody plants was declining, interest in magnolias and the Magnolia Society was expanding – worldwide. Dr. Craig Hibben, one of Lola’s former supervisors at BBG, mentioned to me recently that along with all of her success, “some of the bureaucracy at the BBG still didn’t know what a jewel they had.” Well, we do, Lola! Tonight, it is with great pleasure we honor you with the D. Todd Gresham Award. Congratulations and thank you, Lola Koerting.

Stephen A. Spongberg

Stephen A. Spongberg received his Ph.D. in Botany from the University of North Carolina at Chapel Hill. In 1970 he began his 28-year tenure at the Arnold Arboretum of Harvard University, first as Assistant Curator, later as Horticultural Taxonomist as well as Editor of the prestigious Journal of the Arnold Arboretum for its final 12 years of its regular publication. It was here where he authored a series of modern treatments of cultivated woody plants. Among these were Lauraceae Hardy in Temperate North America, Styracaceae Hardy in Temperate North America and, of course, Magnoliaceae Hardy in Temperate North America. This 1976 monographic account of the temperate Magnolias was the first detailed and comprehensive treatment since G.H. Johnstone’s 1955 Asiatic Magnolias in Cultivation and J.G. Millais’ Magnolias in 1927. While it superseded Johnstone in scope, it replaced the largely obsolete Millais volume in its accounts of the temperate magnolias. More importantly, Steve’s work quickly inspired others – most notably Neil Treseder (1978) , Dorothy Callaway (1994), Jim Gardiner (1989, 2000) - to build and expand upon what he had started, thus ushering in a prosperity of Magnoliaceae knowledge that had been unimaginable before 1976. Over the past 35 years, Magnoliaceae Hardy in Temperate North America has consistently been one of the most frequently cited references in both popular and scientific Magnoliaceae literature. 2


Issue 90 Of course, Steve’s work went far beyond Magnoliaceae. In 1980 he participated in the Sino-American Botanical Expedition to western Hubei Province in The People’s Republic of China. This historic trip was the first-ever cooperative venture between Chinese and American scientists. In 1990 he authored A Reunion of Trees - a comprehensive history of the global exploration for woody plants. This highly regarded account is listed by the American Horticulture Society as one of the seventy-five greatest garden books published in the 20th century. In 1996 he was awarded the prestigious Gold Veitch Memorial Medal by the Royal Horticultural Society. After his tenure at the Arnold Arboretum in 1998, he became the first director of the Polly Hill Arboretum on Martha’s Vineyard and served six years. Polly Hill said, “When Steve accepted the job, way back when, I felt so lucky I could hardly believe it - he has fulfilled those dreams consistently and beautifully.” Steve continues a vital role at the Arboretum as an honorary board member and Director Emeritus. In 2010, the Stephen A. Spongberg Library was established in his honor. On behalf of the Magnolia Society International, it gives us great pleasure to present the D. Todd Gresham Award to Steve Spongberg.

(L to R) Dick Figlar, Steve Spongberg and Andrew Bunting after ceremony awarding Spongberg with the Gresham Award. They are standing in front of the Polly Hill Arboretum library recently named to honor Spongberg. (photo by Tom Clark) 3


Magnolia

The Magnolia collection at the JC Raulston Arboretum at NC State University

Mark Weathington, Assistant Director and Curator of Collections, JC Raulston Arboretum at NC State University, Raleigh, NC

The JC Raulston Arboretum

The JC Raulston Arboretum (JCRA) is a nationally acclaimed garden with one of the most diverse collections of cold-hardy temperate zone plants in the southeastern United States. As a part of the Department of Horticultural Science at NC State University in Raleigh, NC, the JCRA is primarily a research and teaching garden that focuses on the evaluation, selection and display of plant material gathered from around the world and planted in landscape settings. Plants especially adapted to Piedmont North Carolina conditions are identified in an effort to increase the diversity in southern landscapes. The JCRA’s 10 acres and nursery contains over 8300 accessions of over 5000 different taxa. The JCRA’s location in the central piedmont of North Carolina allows us to grow a wide diversity of plant material. Our temperatures generally range from about -12°C (10°F) to 35°C (95°F), but temperatures much lower and higher are not unknown. The average annual precipitation measures 109cm (43 in) and in most months the area receives about 7.5-10cm (3-4in).

The Magnolia collection

Magnolias have been an important part of the collections of the JCRA from its inception and we are currently applying to be part of the multiinstitution North American Plant Collections Consortium Magnolia collection. The first accessioned magnolia dates to 1977, less than a year after the arboretum founder and namesake, J.C. Raulston, arrived at NC State University. This Magnolia ×loebneri ‘Merrill’ still graces the Klein-Pringle White Garden where it welcomes the spring with a glorious floral display. The JCRA’s Magnolia collection represents a broad diversity of both species and cultivars comprised of 133 different taxa, including 32 species. We currently hold accessions from 8 of the 12 sections of the genus Magnolia, lacking only taxa in the mostly tropical Talauma, Kmeria, and Manglietiastrum sections and our own North Carolina native Auriculata section. We have a particular focus on members of section Michelia, with 19 taxa in this group alone. The complete list of magnolias planted on the grounds of the JCRA can be found on our website (www.ncsu.edu/jcraulstonarboretum) under the “Current Plantings” heading in the “Horticulture” tab. Photographs of many of our magnolias can also be found on the website in the “Photography” section.

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Issue 90 The evergreen plants in section Michelia are especially valuable since they provide structure, and often flowers, during our relatively mild winters. Magnolia ernestii has made a handsome, narrowly upright evergreen tree in the southwest corner of the Japanese Garden where it now towers over the 8ft wall. The glossy green leaves are quite attractive and the flowers, although not terribly showy, are delightfully fragrant when they appear in late winter to early spring. Our plants (another grows in the Winter Garden) were acquired in 1995 and 1997 and have grown to nearly 20ft in that time. Another choice plant in this section rising above the lath house is M. cavaleriei, which begins flowering in December and continues to March. The large, loose white flowers often exhibit winter damage, but can be stunning against the clear blue winter sky. Another section member that hasn’t yet made it out of the nursery is M. compressa, which I collected in Taiwan in 2009. These seedlings come from plants growing at over 2100m (7000ft) in central Taiwan and should prove to be hardy. In the wild these trees had straight, smooth trunks and were identifiable mainly by the oc- Magnolia cavaleriei casional fruit found among the leaf litter on the ground. We hope to be able to distribute this collection in the not too distant future if it proves to be garden-worthy. M. lotungensis in section Gynopodium has been happily growing in our lath house since 1998 and finally consented to flower a decade later. The creamy cup-shaped flowers are quite lovely in April and May, but can be difficult to see since they are generally above the roof of the structure. It forms a very distinctive upright, narrow pyramid with new foliage often tinted red when it first emerges in the spring. I am told it is used as a street tree in Yunnan where it is native and I have seen it growing in gardens in Hangzhou. Nearby in our new Asian Valley from section Gwillimia is a very attractive pinkMagnolia lotungensis flowered form of M. delavayi. The large foliage has suffered some winter damage, but has still flowered well. We will be watching this form closely to see if it proves to be reliably hardy with age.

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Magnolia Another mostly evergreen section, Manglietia, is home to M. fordiana, a lovely narrow-leafed tree with cupped white flowers. Our plants are still relatively young, but I get to enjoy the related and similar M. yuyuanensis as a hedge outside my office in full flower as I write this article in Magnolia fordiana (photo by A. Schettler) late April. Both make beautiful specimens, but can be painfully slow to flower and difficult to propagate. Our hedge was planted with the intention of coppicing in the hopes that the young vigorous shoots would root more readily, but to date we have balked at the seeming sacrilege when confronting them with the pruning saw. The JCRA, of course, also has significant collections of deciduous magnolias in section Yulania, with a multitude of plants ranging from M. amoena to M. zenii. We love the delicate pink to white flowers deepening to burgundy at the base of the tepals in both species and the purplish anthers of the former species, which are reddish in the latter. The large flowers on bare early spring branches of this section are highlights of the eastern end of the Arboretum, where the bulk of the magnolia collection is situated. While we hold significant collections of species magnolias, cultivars also are well represented at the JCRA. Magnolia ‘Coral Lake’ is a particular favorite of visitors because of its very late, large, double pink flowers highlighted with streaks of yellow. It has been thriving at the head of our Scree Garden where its April flowers and upright habit form a colorful sentry. An older selection, but still one of my personal favorites, is M. stellata ‘Chrysanthemiflora’. The clear pink color of the multitude of tepals (36-40) on a small-statured tree are unmistakable Magnolia 'Coral Lake' (photo by A. Schettler) and, in my mind, are 6


Issue 90 unsurpassed by any other pink star magnolia. In a nod of appreciation to the diversity of our own native evergreen magnolias, the collection holds 11 taxa of M. virginiana and 18 of M. grandiflora. The small-leaved selections of M. virginiana ‘Perdido’ and M. v. ‘Coosa’ add an unusual texture to the magnolia collection and should be more widely grown, especially in smaller gardens. The white flowers of both are mediumsized but appear relatively large against the undersized leaves and Magnolia virginiana var. australis 'Coosa' have the clean, lemony fragrance typical of the species.

Increasing awareness

The JC Raulston Arboretum has always endeavored to increase the diversity of the American landscape through evaluation of plant material, display of novel and superior selections, and dissemination of knowledge and plants. Over the last 15 years, the JCRA has distributed thousands of plants to nurserymen, other gardens, and Arboretum members. Among these allotments have been magnolia distributions in larger numbers, including M. sieboldii, M. figo ‘Port Wine’, M. zenii, M. yuyuanensis, M. chapensis, M. laevifolia ‘Michelle’, M. denudata ‘Forrest’s Pink’, and M. insignis, among many others. Hopefully, this results in creating more magnolia enthusiasts in the process. We are in the process of evaluating our collection, making systematic removals of plants which no longer fit into our collection priorities and aggressively adding new forms. Our dynamic collection keeps the JCRA fresh and ensures that there is always something new to see on each visit. After all, life is too short for boring plants.

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Magnolia

Asiatic Magnolias and the UBC Botanical Garden

Andy Hill, Curator-Horticulturist, David C. Lam Asian Garden UBC Botanical Garden and Centre for Plant Research, Vancouver, BC

The University of British Columbia (UBC) Botanical Garden has a fine history of Magnolia study that goes back a half century to the early plantings in the David C. Lam Asian Garden. The 10-hectare (25-acre) garden was originally being developed as a collection of rhododendrons by then Curator Peter Wharton who soon expanded that early vision to include other associated woody plants. Principal among those were the much-loved magnolias, many of which were uncommon, with new species still to be discovered and added to the Garden. Early plantings in the UBC Asian Garden were of section Yulania and included favorite cultivars such as M. dawsoniana ‘Chyverton’, M. sprengeri ‘Claret Cup’, M. s. ‘Copeland Court’, M. s. ‘Wakehurst’, M. campbellii subsp. campbellii ‘Ethel Hillier’ and M. c. subsp. mollicomata ‘Lanarth’. As the goals of research and conservation grew Peter Wharton with Magnolia 'Eric Savill' at UBC Botanical in importance, so did Garden the preference for wildcollected species with known provenance. Valuable seed began to arrive at the Garden through a wide network of magnolia friends and the varied species began to dominate the collections. The Garden’s own expeditions into wild places across Asia were also contributing to the community, with fieldwork carried out in South Korea, China and northern Vietnam.

Fieldwork and research

Perhaps one of the most important of these expeditions was the work done in 2006 on Magnolia sargentiana. Along with Dr. Ya Tang and colleagues from Sichuan University, Peter Wharton was part of a group that was able to locate new ranges of this red-listed species in the Meigu Dafengding Nature Reserve. This helped the Chinese government, which had already established sensitive regions and plant groups, to set up new protection areas and further conservation efforts. Seed was collected and distributed internationally to various botanic gardens and scientific institutions for 8


Issue 90 ex situ study, with a number of specimens added to the UBC Botanical Garden.

Author and guide next to Magnolia dawsoniana

Fieldwork in Asia has continued with recent expeditions to Sichuan Province, in western China. Two trips in 2010 with Quarryhill Botanic Garden, Sichuan University, Shenzhen Botanic Garden and Ya’an Botanic Garden sought to collect a range of data and locations of magnolia species in bloom early in the year, then return to collect seed and supplemental data in the autumn. These expeditions have been successful, with a large number of M. wilsonii, M. sargentiana and M. dawsoniana examined and specimens collected. The geotagged data will be compiled in a new spatial database we are developing to assist in future fieldwork. All of this, hopefully, will add a little more to our collective knowledge of the amazing genus.

The UBC Botanical Garden is committed to the study of Magnolias, both in their native ranges and within our own collections. One project that is just now passing twenty years of activity is the continuing Magnolia Phenology Study. A passionate group of volunteers have recorded observations relating to bloom times—information that will be compared against weather data for that period and examined for trends. We have noticed significant variation in data from year-to-year observations and will soon be able to see exactly what changes have occurred.

Evergreens at the UBC Botanic Garden

Vancouver is fortunate to have a mostly gentle climate. The Asian Garden is in a particularly sheltered spot below a towering canopy of native conifers (Pseudotsuga menziesii, Abies grandis, Thuja plicata and Tsuga heterophylla), and influenced by the Pacific Ocean, which is close by. The temperature rarely drops below -10C/14F. On average, 125cm (50in) of rainfall is measured annually; however, most of that arrives in the winter, making it necessary to irrigate through the summer. We can grow a surprising range of plants and it was an inspired decision early on to begin experimenting with the evergreen magnolias. In an article that appeared in the UBC Botanical Garden Journal, Davidsonia, in 2006, Peter Wharton provided an update on how these evergreen species were performing in Vancouver. At that time he wrote, “A major challenge for many species is sudden cold, often with heavy wet snow, a common winter event in the Pacific Northwest. Branch and crown form, strength of branch and stem attachments, branch flexibility, and the snow 9


Magnolia shedding attributes of leaves are all factors that influence survival and attractiveness under this threat.� This observation proved prescient, especially during this past winter where foul weather arrived unusually early in November (down to nearly -7C (20F), strong winds and heavy wet snow and returned again, nearly as dramatically, at the end of February.

Magnolia sprengeri after an ice storm April 13, 2010

In the five years since that report we have lost a few promising species, including M. doltsopa (section Michelia) and M. floribunda (section Michelia). A few others in very poor condition are scheduled for removal. But there have also been some real stars. Here is a brief update of the Asiatic evergreen species magnolias at the UBC Botanical Garden in 2011. Magnolia aromatica (section Manglietia) - One weak plant, poorly sited with too much shade and drought. Minimal growth, but leaves and buds look little damaged. Not a fine specimen. We are propagating it and expect better luck in another part of the Garden. Magnolia cavaleriei var. platypetala (section Michelia) - Perhaps 90% defoliated from the winter and some broken branches. Not at all happy with the harsh weather of early November. Magnolia chevalieri (section Manglietia) - One of our worst for frost burn and marked leaves, though, if past experience is true, it should recover well through the summer. Magnolia conifera (section Manglietia) - A fantastic tree. Most promising and perfectly content, even after the last winter. Strong, even branching, no breaks...even with minimal protection. Leaves and buds seem almost completely unblemished. We’re very excited about this species and it appears it may bloom well this year.

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Issue 90 Magnolia ernestii (section Michelia) - Another great performer, at least in its sheltered position below our native conifers. Some broken branches but little frost damage to the foliage, though somewhat difficult to tell as it’s now approaching 10m (33ft) in height with a high crown. Magnolia fordiana var. fordiana (section Manglietia) - There are a number of trees and most have looked quite bad for many years. Very spindly growth, yellowed leaves and repeated damage from cold and snow. Possibly improved fertility would help, as well as a less exposed site (our best tree is growing in half shade and our worst, totally open). Magnolia foveolata (section Michelia) - Despite being well protected by the over-story of larger conifers, this tree suffered some significant branch damage from snow loading, including the top 2-3m (10ft) of its central leader. This is truly a shame, because the large glossy leaves and new buds appear mostly to have made it through the cold without too much injury. This was one of Peter Wharton’s favorites and he would argue Magnolia foveolata at UBC Botanical Garden it has great potential for this region. (Photo by Douglas Justice) Magnolia insignis (section Manglietia) - Looks absolutely perfect, as usual. Leaves unmarked and lots of healthy flower buds. This tree receives a fair amount of indirect light and some shelter from nearby conifers that deflect the worst of the winter weather. Magnolia lotungensis (section Gynopodium) - A really lovely tree, surprisingly undamaged by the heavy snows or the cold temperatures. Definitely another one to watch. Magnolia martini (section Michelia) - Two trees -- one terrible and the other just very bad. Many broken branches (over half of the one tree) and both with yellowed and burned leaves, buds and wood. It’s becoming difficult to justify their continued place in our collection. Magnolia maudiae (section Michelia) - Possibly our best of the recent magnolia additions. Unscathed with very strong growth. We have three trees, all Peter Wharton collections and all with some shelter and moist (though not necessarily well-drained) sites. They look terrific.

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Magnolia Magnolia nitida (section Gynopodium) - This young tree is a bit of a surprise for us. It was rediscovered in an overgrown, shady and dry corner of the Garden (during some plant exploration in our own garden!) then somewhat brutally transplanted early last season. In the last year it has grown nearly 0.5m (2ft) and is now approx. 2.5m (8.5ft) tall, and is completely at home. The small, glossy leaves and tiny buds are perfect. Magnolia yunnanensis (section Gynopodium) - This tree is located beside our M. aromatica and suffers the same conditions of dry, poor soil and competition from neighboring plants, of which it is not at all tolerant. It was nearly totally defoliated from this winter and is in serious decline. We are in the process of propagating this tree and hopeful that it will do better elsewhere in the Garden.

Looking ahead

In the coming year, UBC Botanical Garden will participate in a multi-site North American Plant Collections Consortium registration of the genus Magnolia. This will help articulate our commitment to magnolias and firmly place the group as a priority taxon in our policies and planning. The Garden’s position within the University’s organizational structure has changed and we are now part of the new UBC Biodiversity Collections group in the Faculty of Science. This brings increased access to UBC researchers and resources, as well as the outstanding UBC Herbarium. It is our intention to continue to play a lead role in both in situ and ex situ conservation, research and education while developing a beautiful garden (and this genus really does make it so easy) that will delight visitors.

References

WANG, J., TANG, Y., XIE, Z.-H. and ZHANG, M.-Y. (2009), Autecology and conservation status of Magnolia sargentiana Rehder & Wilson (Magnoliaceae) in the Dafengding region, southern Sichuan Province, China. Journal of Systematics and Evolution, 47: 525–534. doi: 10.1111/j.17596831.2009.00051.x. WHARTON, A.P. (2006). Evergreen Magnolias Growing at UBC Botanical Garden, Vancouver, Canada: a Progress Report. Davidsonia 17(4):116-133.

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Issue 90

A comprehensive evaluation of yellow-flowering Magnolias Donna C. Fare, Research Horticulturist, USDA-ARS, US National Arboretum

Introduction

Deciduous magnolias are well adapted to many landscape situations and are highly desirable due to their floriferous nature. About 800,000 flowering magnolias are sold each year in the US and about 10% of the nurseries that grow them are located in Tennessee (USDA, 2010). Yellow-flowering deciduous magnolias are becoming popular landscape plants because they offer an unusual color palette (Knox, 2002). There are very few yellow-flowering small trees in the landscape plant inventory. This research project was conducted at the Tennessee State University (TSU) Nursery Research Center located in the heart of the nursery industry in Tennessee on the border of USDA Hardiness Zones 6 & 7. The area is known as a climatic and geographic transition zone. Plants raised in this area can be used in landscapes in as far north as Zone 5 and as far south as Zone 8. Plant evaluations made in transition zones are ideal because results can be utilized over a wide geographic and climatic area. The primary objective of this research project was to compare yellowflowering magnolias for flower color intensity, flower size and duration, as well as growth rate and canopy form. A secondary goal was to develop a performance record of magnolias planted in a replicated trial in one location to assist plant breeders for future plant development.

Materials and Methods

Many selections of yellow-flowering magnolias are only available in low numbers and small sizes. For this project, plants were purchased, grown in a #3 or #5 container for a year, and planted in the evaluation plot the following spring. Magnolias were first planted in March 2006 in a field plot with 4.6 m (15 ft) in-row spacing and 3.7 m (12 ft) between rows in a well-drained silt loam soil (Waynesboro). Each magnolia selection was planted in a randomized block design with three single plant replications. Plants were maintained with traditional management, including fertilization, mulching and weed control. Pruning was limited to removing branches from the trunk about 61 cm (24 in) above the soil line. Irrigation was applied during the growing season in periods of drought. In March 2007, unseasonably warm temperatures occurred. Many plants had broken dormancy and were leafing out. Within a couple of weeks in early April 2007, a hard freeze occurred, lasting for several days. Many of the magnolia selections were killed or suffered severe dieback. Plantings were reestablished. Currently, we have 37 selections of yellow-flowering magnolias under evaluation (Magnolia Society, 2010). Due to the differ13


Magnolia ent planting dates (Table 1), growth data presented in Tables 1 and 2 were calculated by subtracting height and caliper measurements in the spring from fall measurements to determine growth during each year. In 2009 and 2010, 5 leaves were selected from each plant to determine leaf area (only data from 9 June 2010 shown). Flowering duration was determined from recording the first flower to the last flower when tepal color no longer had a visual impact. On the first day that selected flowers opened, three were selected to determined tepal color using the Royal Horticultural Society color chart and a portable spectrophotometer (Minolta 2600d) (only data from April 6 and April 9, 2010 shown). All data was statistically analyzed using the general linear model in SAS 9.1. Mean separation was performed with Fisher’s protected LSD with alpha = 0.05.

Results and Discussion

In 2007, plant growth was slow due to the effect of the April freeze. During 2008 to 2010, Magnolia ‘Goldfinch’, M. ‘Gold Star’ and M. ‘Banana Split’ had the greatest average height growth of 114 cm, 99 cm and 97 cm, respectively (Table 1). The slowest growing selection was M. ‘Golden Sun’ with an average of 22 cm during 2009 to 2010. Slow growth appears to be typical for many of the yellow flowering magnolia selections during the first year or two after transplanting. Yearly height growth increased after the third year in the test with many selections. Table 1. Date planted and height growth of selected yellow-flowering Magnolia selections in McMinnville, Tenn from 2006 - 2010. Height growth, cm Selection

Y

Z

Date Planted

2006

Anilou

2010

-

-

-

-

Banana Split

2009

-

-

-

109 a

2010

-

-

-

-

2010

-

-

-

-

2006

97 a

2009

-

-

-

2009

-

-

-

-

2010

-

-

-

-

Daybreak

2007

-

2d

18 cde

Elizabeth

2006

-

49 cd

Evamaria

2009

Y

Blue Opal Brenda

Y

Y

Butterflies Carlos Coral Lake Daphne

Y

Y

Y

X

42 bc -

2007

23 bcd

-

70 bcd

-

58 a-f 69 a-f

85 a-e

2010 85 bcd 78 bcd 115 ab 73 bcd

7g

74 bcd

76 a-f

86 bcd

Gold Cup

2010

-

2006

100 a

Golden Gala

2009

-

-

-

70 a-f

90 bcd

Golden Gift

2007

-

107 a

35 e

31 efg

24 e

Golden Pond

2010

-

-

-

-

Y

2010

-

-

-

-

Golden Sun

2009

-

-

-

Goldfinch

2008

-

-

Y

14

47 abc

-

2009

Gold Star

Golden Rain

-

2008

239 a

85 bc

31 efg

47 c-f 109 a

80 bcd

65 cde 148 a


Issue 90 Z

Table 1. Cont. Selection

Height growth, cm

Y

Date Planted

2006

Y

2010

-

-

-

-

-

Y

2010

-

-

-

-

-

Y

2010

-

-

-

-

-

2008

-

-

-

-

2008

-

-

-

2010

-

2007

-

49 ab

53 cd

56 b-f

74 bcd

86 bc

91 a-d

69 cde

Green Bee

Honey Liz Illini Gold

Illini Moonlight Judy Zuk Koban Dori

Y

Lois Miss Honeybee Petit Chicon

Y

Skyland’s Best

Y

Solar Flair

Y

2007

-

2008

-

2009

78 a-f

2008

-

2d

-

-

-

-

2010

-

-

-

-

Stellar Acclaim

2007

Sun Ray

2006

Sun Spire

2007

30 bc 38 bc -

95 bcd

-

2010 2006

2010

-

-

24 bcd

49 cd

74 a-f

70 bcd

45 abc

53 cd

68 a-f

103 abc

2d

77 bcd

52 c-f

74 bcd

5 bcd

39 cde

71 a-f

72 bcd

Sunburst

2006

79 ab

22 bd

60 bcd

27 fg

66 de

Sundance

2006

55 ab

19 bcd

83 bc

63 a-f

78 bcd

Sunsation

2006

-

Yellow Bird

2008

-

Yellow Lantern

2009

LSD

23 bcd -

82 a-e

51 de

133 b

65 bcd

61 a-f

68 cde

104 abc

75 bcd

-

-

-

50

2

75

54

6

Z Height growth in 2006 = measurements made in Dec 2006 - April 2006; 2007 height growth = measurements made in November 2007 - March 2007; 2008 height growth= measurements made in December 2008 - March 2008; 2009 height growth = measurements made in November 2009 - March 2009; 2010 height growth = measurements made in November 2010 - March 2010. Y

Selections have been planted in the evaluation, but have not been planted long enough to report results. X

Treatments followed by the same letter are not significantly different. Means separated using Fisher's protected LSD, α ≤ 0.05.

Trunk diameters were measured 30 cm (12 in) above the soil surface. Trunk growth averaged from 9 mm to 29 mm during the test (Table 2). M. ‘Carlos’, M. ‘Yellow Lantern’, M. ‘Sundance’, M. ‘Gold Star’ and M. ‘Golden Gala’ had the most trunk diameter increase and averaged over 25 mm (1 in) growth per year. M. ‘Golden Gift’, M. ‘Daybreak’, M. ‘Golden Sun’ and M. ‘Solar Flair’ had the least trunk diameter growth increase with yearly averages of 9 mm, 11 mm, 12 mm and 14 mm, respectively. Other selections had an intermediate increase in trunk diameter. Canopy growth was calculated from an average of 2 canopy widths measured from one drip line perpendicular to another in 2008, 2009 and 2010 (Table 2).

15


Magnolia Table 2. Trunk diameter growth and canopy width of selected yellow-flowering Magnolia selections in McMinnville, Tenn from 2007 - 2010. Trunk caliper growth, mmZ Canopy width, cmZ Selection 2007 2008 2009 2010 2008 2009 2010 Banana Split 19 ab 19 b 16 gh 34 ghi 72 fgh Y Butterflies 23 a 27 bc 25 ab 20 b 158 a 155 ab 225 ab Carlos 21 ab 30 ab 12 gh 54 e-i 128 d-h Daybreak 2e 14 ab 16 b 8 gh 25 i 62 h Elizabeth Evamaria

Gold Star Golden Gala Golden Gift Golden Sun Goldfinch Judy Zuk Lois Miss Honeybee Solar Flair Stellar Acclaim Sun Ray Sun Spire Sunburst Sundance Sunsation Yellow Bird Yellow Lantern LSD

22 a

19 bcd

5b

58 a

14 ab

2e 6 de 19 bcd 12 cde

5b

13 22 13 33 21 17 19

9

15

17 a 21 a 18 a

cde bcd cde b bcd cde bcd

2 28 10 28 14 12 29 15 19 30 19 18 2 16 1 2 22 20 26 49

b ab ab ab ab ab ab ab ab a ab ab b ab ab b ab ab ab

16 10 37 29 10 12 24 21 21 24 22 21 44 17 11 63 30 16 26 1

b b ab ab b b ab b b ab ab b ab b b a ab b ab

109 14 125 29 53 17 21 6 75 16 83 51 143 13 104 14 25 48 22 47

bcd gh abc fgh efg gh gh h def gh cde e-h ab gh bcd ab gh e-h gh

119 48 163 70 83 27 58 28 113 64 106 78 161 34 103 162 54 85 52 59

abc f-i a c-i c-i hi d-i ghi a-d c-i a-e c-i a ghi b-e a e-i c-g e-i

149 80 231 160 99 68 104 68 147 110 155 143 207 75 142 209 88 122 119 75

cde e-h a a-d d-h gh d-h gh c-f d-h bcd c-g abc e-h c-g abc d-h d-h d-h

Z Trunk diameter growth was not meaured in 2006 and canopy width was not measured in 2006 and 2007; 2007 trunk diameter = measurements made in November 2007 - March 2007; 2008 trunk diameter and canopy width = measurements made in December 2008 - March 2008; 2009 trunk diameter and canopy width = measurements made in November 2009 - March 2009; 2010 trunk diameter and canopy width = measurements made in November 2010 - March 2010. Y

Treatments followed by the same letter are not significantly different. Means separated using Fisher's protected LSD, ι ≤ 0.05.

16


Issue 90

By 2010, distinct canopy shapes were prominent with several cultivars. M. ‘Sun Ray’, M. ‘Gold Star’ and M. ‘Butterflies’ had the widest canopies among the selections and could be labeled as broadly ovate. These plants, along with M. ‘Solar Flair’, M. ‘Elizabeth’ and M. ‘Sundance’, were replanted in 2007 after the freeze and had been evaluated for the longest period of time. M. ‘Sunburst’, M. ‘Sun Spire’ and M. ‘Golden Gala’ had the most upright growth habit and will probably become more distinct with age. Other selections in the evaluation have not been evaluated long enough to determine a distinct canopy form (Figure 1). Figure 1. Canopy form of selected yellow-flowering Magnolias in McMinnville, Tenn. Images were taken in summer 2010.

Butterflies

Elizabeth

Golden Gala

Lois

17


Magnolia

Solar Flair

Sunburst

Sundance

Sun Ray

Sun Spire

Yellow Bird

Foliage

Foliage on the yellow-flowering magnolias were distinctly different among selections and a few with large leaves had an impact on the visibility of the spring flowering. A CID leaf area meter, CI-203, was used to measure the surface area of leaves to determine the leaf size (Figure 2). M. ‘Carlos’, M. ‘Golden Gala’, M. ‘Sunsation’ and M. ‘Yellow Lantern’ had the 18


Issue 90 largest leaves, which presented a coarse texture leaf form. In contrast, M. ‘Butterflies’, M. ‘Gold Star’, M. ‘Golden Gift’, M. ‘Miss Honeybee’ and M. ‘Sunburst’ had the smallest leaves. Figure 2. Leaf area of selected yellow-flowering Magnolias in McMinnville, TN on 9 June 2010. Yellow Lantern Yellow Bird Sun Spire Sunsation Sunburst Sun Ray Sundance Stellar Acclaim Solar Flair Miss Honeybee Lois Judy Zuk Goldfinch Golden Sun Golden Gift Golden Gala Gold Star Eva Maria Elizabeth Daybreak Carlos Butterflies Banana Split 0

50

100

150

200

250

Leaf area, cm2

Powdery Mildew

Powdery mildew (Erysiphe magnifica) has developed into a serious problem in the evaluation (Figure 3). The percent of powdery mildew (PM) incidence on individual leaves and the percent of incidence on the total leaves per tree were rated during the summer months in 2008, 2009 and 2010 (only 16 Aug 2010 data shown in Table 3). All selections had some incidence of PM; however, by mid to late summer several selections had severe incidence. Greater than 40% of the leaf area of M. ‘Daybreak’, M. ‘ Evamaria’, M. ‘Golden Gala’, M. ‘Golden Sun’, M. ‘Solar Flair’, M. ‘Stellar Acclaim’, M. ‘Sunburst’, M. ‘Sunsation’ and M. ‘Yellow Bird’ had become affected by PM and over 60% of all the leaves on the plants had PM. Although only 15% of individual leaf surface of M. ‘Gold Star’ was affected with PM, every leaf on the tree had PM. M. ‘Sun Spire’ and M. ‘Carlos’ showed the least amount of PM on individual leaves and on the total leaves per tree. Two popular selections in the nursery trade, M. ‘Butterflies’ and M. ‘Elizabeth’, had PM similar to M. ‘Sun Spire’ and M. ‘Carlos’. In Figure 4, the progression of PM during 2010 is shown with M. ‘Gold Star’, M. ‘Solar Flair’ and M. ‘Stellar Acclaim’. Near the end of the summer, new foliage growth does not have the presence of PM, probably due to the unfavorable host environment. 19


Magnolia Figure 3. M. 'Gold Star' and M. 'Stellar Acclaim' foliage with incidence of powdery mildew, photographed September 2010.

Gold Star

Stellar Acclaim

Table 3. Percent of powdery mildew incidence on individual leaves and percent of total leaves affected on 16 Aug 2010 with yellow-flowering Magnolia.

Selection Banana Split Butterflies Carlos Daybreak Elizabeth Evamaria Gold Star Golden Gala Golden Gift Golden Sun Judy Zuk Lois Solar Flair Stellar Acclaim Sunburst Sundance Sun Ray Sun Spire Sunsation Yellow Bird Yellow Lantern LSD

% powdery mildew on individual leaves 20.0 10.0 13.0 50.0 10.0 45.0 15.0 43.0 20.0 60.0 17.0 20.0 60.0 47.0 50.0 10.0 13.0 3.0 43.0 63.0 30.0 29

cdeZ de de ab de ab de abc cde a de cde a ab ab de de e abc a bcd

Y

% powdery mildew on total leaves per tree 20.0 27.0 17.0 90.0 25.0 95.0 100.0 60.0 70.0 65.0 30.0 47.0 100.0 100.0 80.0 20.0 30.0 3.0 83.0 90.0 23.0 21

fg fg g abc fg ab a de b-e cde fg ef a a a-d fg fg g a-d abc fg

Treatments followed by the same letter are not significantly different. Means separated using Fisher's protected LSD, ι ≤ 0.05.

20


Issue 90 Figure 4. Powdery mildew rating on 5 selected yellow-flowering Magnolias during 2010. 70

Percent Powdery Mildew on Tree Canopy

60

50

40

Butterflies Elizabeth Gold Star

30

Solar Flair Stellar Acclaim

20

10

0 17-Jun 24-Jun

1-Jul

8-Jul

15-Jul

22-Jul

29-Jul

5-Aug 12-Aug 19-Aug 26-Aug

2-Sep

Evaluation Date

Time of flowering, flowering duration, flower size and color was recorded each spring. Flowering duration is shown in Figures 5 and 6 for 2009 and 2010, respectively. Each yellow bar represents the flowering duration from beginning to end. Often, the peak bloom period is for a short period of time near the middle of the bar. M. ‘Butterflies’ was the earliest to bloom in 2009 and 2010 followed by M. ‘Elizabeth’, which had one of the longest flowering periods during 2009 and 2010. During 2010, spring temperatures were unseasonably warm during the flowering period and flowers matured very quickly; thus, the flowering period was shorter for most selections than in 2009. Each green bar represents leaf-out from the time the foliage was at least 50% unfurled. Some selections, i.e., M. ‘Sun Spire’, M. ‘Sunburst’ and M. ‘Yellow Bird’ (Figure 7), leafed-out during the flowering period, which masked the impact of the yellow flowers. Observations show the foliage consistently unfurls and fully expands in a short time frame, about 10 to 14 days. The early green foliage thus masks the yellow tepals, regardless of the yellow intensity.

21


Magnolia

Figure 5. Bloom and leaf-out duration of selected yellow-flowering Magnolias in spring 2009. Yellow bars represent the flowering duration and green bars represent the leaf-out period. Yellow Bird Sunsation Sun Ray Sun Dance Sun Burst Stellar Acclaim Solar Flair Lois Judy Zuk Golden Gala Gold Star Elizabeth Butterfiles Banana Split 10 Mar 09 18 Mar 09 24 Mar 09 31 Mar 09

6 Apr 09

16 Apr 09

22 Apr 09

28 Apr 09

6 May 09

Figure 6. Bloom and leaf-out duration of selected yellow-flowering Magnolias in spring 2010. Yellow bars represent the flowering duration and green bars represent the leaf-out period. Yellow Bird Sunsation Sun Ray Sun Dance Sun Burst Stellar Acclaim Solar Flair Lois Judy Zuk Golden Gala Gold Star Elizabeth Butterfiles Banana Split 25 Mar 10 1 Apr 10

6 Apr 10

22

9 Apr 10 14 Apr 10 20 Apr 10 30 Apr 10 6 May 10


Issue 90 Figure 7. Images of selected yellow-flowering Magnolias in McMinnville, Tenn.

Butterflies

Elizabeth

23


Magnolia

Golden Gift

Lois

24


Issue 90

Solar Flair

Sunburst

25


Magnolia

Sunsation

Sun Spire

26


Issue 90

Yellow Bird

A portable spectrophotometer (Minolta 2600d) was used to measure color intensity. Three parameters in the following model represent the lightness of the color: L* at 0 = black and L* at 100 = white; a* with negative values indicate green while positive values indicate magenta and its position between yellow and blue; and b* with negative values indicate blue and positive values indicate yellow (Table 4). The Royal Horticulture Color Chart was used to define tepal color. Samples were read near solar noon on 6 April 2009 and 9 April 2010. Tepal color varied markedly from the inner side to the outer side and from the basal end to the tip. Some magnolias had flowers with an intrusion of pink and in some cases the prominence of pink overwhelmed the yellow, as seen in M. ‘Coral Lake’, M. ‘Daybreak’ and M. ‘Evamaria’. All reported measurements in this test were made near the center of the tepal on the outer side. There are differences in the tepal color in this test compared to colors reported in the Magnolia Cultivar Checklist and other notable sources (Robinson, 2006). This is to be expected due to the maturity of the flower, location of the plant and expected differences from year to year (Knox, 2001). Since all colors are detected with the spectrophotometer, more precise color intensity can be measured and provide results similar to what the 27


Magnolia human eye perceives. Based on the parameter b*, the higher the number, the more yellow the color; therefore M. ‘Judy Zuk’ and M. ‘Yellow Bird’ have the highest yellow reading. M. ‘Sun Spire’, M. ‘Sundance’, M. ‘Gold Star’, M. ‘Golden Gala’ and M. ‘Stellar Acclaim’ had the lightest yellow intensity with b* values of 21.4, 22.2, 22.4, 22.6 and 22.8, respectively.

Conclusion

Table 4. Color parameters of selected yellow-flowering Magnolias determined by a portable spectrophotometer, Minolta 2600d. Color parameters, April 2009Z Selection L* a* b* Banana Split 73.9 -2.8 28.1 Butterflies 73.1 -2.7 32.7 Elizabeth 71.2 -0.6 33.6 Gold Star 73.5 -2.1 22.4 Golden Gala 74.2 -2.5 22.6 Golden Gift 70.2 -1.2 32.3 Golden Sun 73.1 -2.4 25.0 Judy Zuk 66.7 1.8 38.9 Lois 72.9 -1.8 28.2 Solar Flair 68.8 -3.2 30.6 Stellar Acclaim 67.4 0.6 22.8 Sun Ray 72.7 -1.0 31.2 Sun Spire 70.2 -0.8 21.4 Sunburst 71.1 -1.3 25.9 Sundance 75.2 -3.2 22.2 Sunsation 69.2 -2.3 26.9 Yellow Bird 68.3 -2.1 34.0

RHCY 6 April 2009 9 April 2010 4c 2d 4d 4d 6d 6d 5d 8c 4c 4c 5d 2d 4d 5d 6d 2d 8c 6d 5d -

Z

L* at 0 = black and L* at 100 = white; a* with negative values indicate green while positive values indicate magenta and its position between yellow and blue; and b* with negative values indicate blue and positive values indicate yellow. Spectrophotometer measurements are taken excluding the specular reflection to provide measurement results similar to those observed by the human eye.

Y

Royal Horticultural Colour Chart

A comprehensive replicated evaluation of new and familiar yellow-flowering magnolias in one location will benefit magnolia connoisseurs, the nursery industry and prospective plant breeders. In time, more valuable information will be collected as the plants mature in this evaluation. The palette of yellow color is well represented with the Magnolia selections from border-line creamy yellow to distinctly yellow in color (Cover, 2009). However, as yellow-flowering magnolias become more widely known, many selections may be less popular for the common landscape and will serve only as a breeding line for developing improved selections. Time of flowering is critical for plants in US Hardiness Zones 6 and 7. Early spring frost (and freezes) can be detrimental on spring flowering as well as the leaf-out period. In this evaluation, many selections leafed-out during the 28


Issue 90 flowering period which caused the flowering to have less impact because the yellow tepals were masked by the early green foliage. This timing, as well as flower color, will be critical to the popular success of many yellowflowered selections (Tubesing, 1998). Another issue that needs to be addressed is the compatibility of the root system. Several individual plants have died or are showing signs of graft incompatibility. Swollen stem tissue above and below the bud union is becoming more prevalent as some of the plants mature. Several propagators queried revealed that three root stocks are routinely used: Magnolia ‘Jane’, M. kobus or M. acuminata; however, the root stocks of the plants in this evaluation are not known. Further research is needed to identify the most compatible root stock for the yellow-flowering Magnolia hybrids.

Acknowledgement

This has been an interesting and challenging research project. Many thanks to The Magnolia Society International for funding this research project!

References

Cover, S. 2009. The performance of yellow magnolia hybrids in a modified continental climate. Magnolia 44(86):5-17. Knox, G.W. 2002. Yellow flowering magnolias for Florida and the Gulf Coast. Proc. of the Southern Nursery Assoc Res. Conf. 47:637-639. Knox, G.W. 2001. New and improved deciduous magnolia cultivars. Comb. Proc. Intl. Prop. Soc. 51:601-603. Magnolia Society, Inc. 2010. Magnolia Cultivars Checklist, http://www. magnoliasociety.org/checklist_ndx.html (accessed 16 Nov 2010). Robinson, M. 2006. Yellow magnolias – an English view. Royal Horticultural Society. http://www.rhs.org.uk/plants/yellowmagnolias.asp (accessed 7 Feb 2006). Royal Horticultural Society and Flower Council of Holland. 1986. RHS colour chart. RHS, London, UK. Tubesing, C. 1998. Sorting out the yellow magnolias. Comb. Proc. Intl. Prop. Soc. 48:312-314. USDA. 2010. U.S. Department of Agriculture, National Agricultural Statistical Service (USDA-NASS) 2009 Census of Horticultural Specialties. http://www.agcensus.usda.gov. (accessed 17 Nov 2010). 29


Magnolia

Ploidy level, genome size, and the music of Magnolias

Kevin Parris, Arboretum Director, Spartanburg Community College, Spartanburg, SC This article is adapted from Parris et al., (2010) Dedication This article is dedicated to the visionary breeders of Magnolia that have gone before us, and is presented to those that work today to expand the boundaries and fill in the gaps of a collective genome that surely inspires anyone with an appreciation of plants. The experiences of the recent 2011 MSI Annual Meeting in Providence, RI, were the inspiration I needed to turn the findings of this research into a format that I hope will be embraced by a wonderfully varied audience. Introduction Under the direction of Tom Ranney of North Carolina State University, I began a survey of genome sizes of a wide array of Magnolia taxa in 2008. The study was officially concluded in 2010 for statistical analyses, but will unofficially continue to be amended as additional species, hybrids, and cultivars of interest become available to study. To understand the reproductive biology of Magnolia species, one must understand polyploidy. Polyploidy is the presence of multiple sets of chromosomes, above the diploid level (2n) within the somatic (vegetative or body) cells of an organism. Polyploidy is extremely rare in animals, but surprisingly common in plants. Magnolias naturally range in ploidy level, with species being either 2n, tetraploid (4n), or hexaploid (6n). Previous sources that include compilations of chromosome counts or ploidy levels used for this study include Callaway, 1994; Chen et al., 2000; Santamour, 1970; and Treseder, 1978. Since we know from chromosome counts that diploid magnolia species have 38 chromosomes, and the haploid gametes (n) have 19, we completely communicate the chromosomal content of a diploid with the Figure 1: Range of polyploidy in Magnolia. expression 2n=2x=38, tetraploid as 2n=4x=76, and hexaploid as 2n=6x=114, with the value before the x representing the complete sets of chromosomes present. 30


Issue 90 This, of course, has significance to breeders because a cross between species of different ploidy levels will favor the higher ploidy parent. This is why the “Little Girl” Hybrids (Magnolia liliiflora (4x) × M. stellata (2x)) most closely resemble the M. liliiflora parent. The greater the difference in ploidy level, the greater the offspring will favor the higher ploidy parent, as evidenced in the Freeman Hybrids (M. grandiflora (6x) x M. virginiana (2x)), which pass as a typical M. grandiflora to all but the most trained eye. When hybrids such as these are developed, we can typically confirm hybridity by closely observing morphological characters. To be certain, chromosome counts can be performed. Since many Magnolia species are polyploids with high chromosome numbers, traditional cytology based upon light microscopic examination is a difficult and time-consuming process. Flow cytometry has proved to be an efficient means of estimating genome size and associated ploidy level (Doležel et al., 2007; Jones et al., 2007). A flow cytometer is essentially a cell counter which can illuminate the stained genetic material within cells. The measured fluorescence generated is displayed in the form of a histogram. We sampled over 300 accessions from various sources that included 62 species, 125 hybrids, and 16 induced polyploids representing taxa from each subgenus of Magnolia as well as both species of Liriodendron, the only other genus in family Magnoliaceae, per Figlar and Nooteboom (2004). Nuclei from newly expanded leaf or tepal tissue were Figure 2: Author running samples through a flow cytometer extracted, stained with at the NCSU Mountain Horticultural Crops Research and 4’, 6-diamidino-2- Extension Center. phenylindole (DAPI), and then analyzed (minimum of 2500 nuclei per sample) using a flow cytometer (PA-I; Partec, Münster, Germany) to determine relative holoploid 2C DNA (whole genome) content, following the methods of Jones et al. (2007). Genome sizes were determined by comparing mean relative fluorescence of each sample with an internal standard, Pisum sativum ‘Ctirad’, with a known genome size of 8.76 picograms (one picogram = one trillionth (10-12) of a gram) (Greilhuber et al., 2007). Holoploid, 2C DNA contents were calculated as: 2C = DNA content of standard x (mean fluorescence value of sample ÷ mean fluorescence value of the standard). Because tetraploid Magnolia taxa have similar genome sizes to P. sativum ‘Ctirad’, Magnolia virginiana ‘Jim Wilson’ (3.92 pg) was used as a secondary standard. Therefore, the objectives of this study were to determine the genome sizes and relationships to ploidy levels of a diverse collection of species, hybrids, and cultivars of Magnolia to 1) develop an extensive database of ploidy levels for use by magnolia breeders, 2) determine the 31


Magnolia ploidy levels of plants that were chemically treated to artificially induce polyploidy and 3) confirm hybridity of interploid and interspecific (when parents vary substantially in genome size) crosses. Figure 3: Typical histogram with peaks generated by two samples of differing genome size.

Resources The collection of samples for this study was an extremely rewarding exercise. The NCSU Mountain Crop Improvement Lab was a primary source of accessions. Multiple trips were made to Magnolian Grove Arboretum, the garden of Dick and Anita Figlar. Dick eagerly advised me as I worked my way through samples obtained from the various taxonomic sections of Magnolia. Pat McCracken also generously hosted me on a collection trip and provided samples from numerous taxa. Another substantial contributor of samples was Greg Paige of the Bartlett Tree Research Laboratory, and with the help of David Kruse-Pickler of the San Francisco Botanic Garden I was able to turn a family vacation into a collection opportunity. On another family trip to Washington DC, I was privileged to spend time with Richard Olsen of the U.S. National Arboretum and take a glimpse at the hand-written notes of breeders such as Frank Santamour, William Kosar, and Francis de Vos. Richard also tracked down some significant accessions that led to key findings. Other significant contributions were made from Charles Tubesing of the Holden Arboretum and breeders Dennis Ledvina of Green Bay, Wisconsin, and Bill Smith of Richmond, Virginia. In the past year I have been able to meet both Dennis and Bill and I now know what has driven the likes of these gentlemen and so many others to keep pushing the boundaries of magnolia diversity. The collection and testing of so many samples may have turned into a painfully repetitive exercise if it were not for the immense respect I have developed for the individuals that brought species into cultivation and 32


Issue 90 escorted scores of hybrids into existence. Without their work, this study would have never been possible. Each sample I held was a piece of living history. Nevertheless, I was using modern technology to measure the relative weight of the genetic material present in the average cell of each named plant, thus turning the product of a plant explorer or breeder’s work into a cold number derived from a mathematical equation. Having adventured with friends from the Magnolia Society International to some of the world’s finest assemblies of Magnolia, I recognize these plants are not the outcome of equations. They are the results of nature, combined with the human qualities of hope and frustration, anticipation and tenacity, passion and heartache. But the numbers Bill Smith and Kevin Parris with some of Bill’s have consequence, and by better new hybrid seedlings at Lewis Ginter Botanic understanding them, greater hope Garden, May 2011. with less heartache may be realized. Data analysis The first step in analyzing data was to determine the mean relative genome size of each species and the section they represent (Tables 1 and 2). As expected, a statistical difference in genome size occurs between taxa of differing ploidy levels. This allows us to clearly illustrate the ploidy level of a sample without performing a chromosome count. Also important was the fact that genome size within each species and taxonomic section had insignificant variation. Another important detail to draw from Table 1 is that a statistic difference in genome size can occur between species of different taxonomic sections within the same ploidy level. For example, hybridity can be confirmed in a group of seedlings from a cross between Magnolia virginiana (Section Magnolia) and Magnolia insignis (Section Manglietia) when the plants are large enough to spare just a small portion of one leaf, before intermediate morphological characters become pronounced. This can save breeders the time and expense of cultivating errant progeny to maturity. Table 2 is condensed in this article to display only the means for each species, rather than reporting all cultivars surveyed. In the case of M. virginiana and M. grandiflora, numerous cultivars were surveyed, with no significance in genome size found. In other species with obscure availability, such as M. sinica, the mean genome size reported is derived from only one accession. Under M. grandiflora, several cultivars previously 33


Magnolia reported to be interploid hybrids are listed to clarify their confirmed ploidy level and species designation. The cultivar ‘Charles Dickens’ has been suggested to have been the result of a cross between M. grandiflora and M. macrophylla (2n=2x=38), but it is hexaploid, aligning it entirely with M. grandiflora. 'Griffin', 'Riegel', and 'Sweet Summer’ are three cultivars which were also thought to have been of hybrid origin, but their genome size is consistent with other M. grandiflora cultivars. Had they been the product of a cross with M. virginiana, their genome size would have been that of a tetraploid. Figure 4: Histograms illustrating discernable and indiscernible peaks.

Table 3 summarizes the results of many hybrids that were surveyed. The results were enlightening. Evidence for successful hybridization between plants of different ploidy levels was apparent based on analysis of genome sizes. In many cases interploid hybrids were substantiated. These include the following within subgenus Magnolia: (M. grandiflora (6x) × M. virginiana (2x)) ‘Maryland’ with an intermediate genome size of 7.49 pg, and also a seedling of ‘Maryland’ from Magnolian Grove Arboretum which was likely open pollinated by M. grandiflora. This accession had a genome size of 9.00 pg, consistent with a pentaploid derived from a (4x × 6x) cross. An unnamed plant at the U.S. National Arboretum with similar appearance to M. ‘Maryland’ was found to have a genome size of 5.62 pg, consistent with a triploid, suggesting a hybrid of M. grandiflora (6x) x M. virginiana (2x) had been backcrossed to M. virginiana. An intermediate tetraploid condition was determined for M. insignis (2x) × M. grandiflora ‘Kay Parris’ (6x) which had an 8.50 pg relative genome size. In addition to the M. virginiana × M. insignis cross mentioned earlier, the following 34


Issue 90 interspecific, intraploid hybrids were confirmed by intermediate size; M. yuyuanensis × M. virginiana, M. ‘Silk Road’ × insignis, and very recently (not included in Table 3) M. insignis × M. fraseri. Within subgenus Yulania, confirmed interploid hybrids were numerous. Verification of hybridity was readily confirmed for the U.S. National Arboretum’s Kosar/ de Vos hybrids. M. liliiflora (4x) × M. stellata (2x) had genome sizes ranging from 6.28 to 6.69 pg, consistent with triploids. Numerous putative pentaploid Flow cytometry was used to verify this seedling was hybrid cultivars, derived tetraploid (8.50 pg), confirming the first successful cross from crosses of (6x × 4x) between M. insignis and M. grandiflora. species or hybrids, were also verified. These hybrids include: ‘Alexandrina’, ‘Angelica’, Apollo’, ‘Blushing Belle’, ‘Butterflies’, ‘Elizabeth’, ‘Galaxy’, ‘Gold Finch’ and ‘Spectrum’ with 2C genome sizes ranging from 10.11 to 11.02 pg. Hybrids arising from parents with odd ploidy levels (5x or aneuploids) were prevalent and had highly variable genome sizes. Magnolia ×soulangeana, a pentaploid hybrid between M. denudata (6x) and M. liliiflora (4x) exhibits fertility in initial F1 hybrids and subsequent generations (McDaniel, 1968), and, when used as parents, gave rise to apparent aneuploid progeny ranging from ~4.6 to ~8.5x, based on genome size. Fertility among M. ×soulangeana cultivars has been examined previously and it was found that pollen viability generally increased with increasing ploidy level above 5x (Santamour, 1970). Relative 2C genome sizes determined here support cytological findings by Santamour (1970) that the cultivars ‘Lennei’ and ‘Grace McDade’ are septaploid (7x) or higher. Other taxa in Table 3 of approximately septaploid genome size include M. ‘Andre Leroy’, M. ‘Manchu Fan’, M. ‘Sunsation’, and M. ‘Todd Gresham’. Each of these hybrids has a parental combination that theoretically could yield 7x offspring. Unreduced gametes can lead to higher than expected genome sizes or ploidy levels in Magnolia hybrids (McDaniel, 1968; Santamour, 1970). In subgenus Yulania, the relative genome size of M. acuminata (4x) × M. stellata (2x) ‘Gold Star’ was determined to be 8.22 pg, consistent with the genome size of a tetraploid. This suggests this cultivar is the result of pollination from an unintended source, or the product of an unreduced 35


Magnolia gamete from M. stellata. The realization that M. ‘Gold Star’ is tetraploid explains why it has been successfully used as a fertile parent in several crosses. No triploid hybrids were found to be parents of any hybrid surveyed in this study, indicating triploids may typically not be fertile. Table 4 documents the confirmation of several induced polyploids. In some cases, the artificial induction of polyploidy in Magnolia also can enhance ornamental characteristics, including thicker leaves and larger flowers with thicker petals that persist longer (Kehr, 1985). Crosses between species with varying ploidy levels may yield hybrids with nonstandard chromosome numbers that can result in reduced fertility or sterility. Because of these constraints, Magnolia breeders have attempted to induce new polyploids to overcome these limitations, yet most of these putative polyploids have never been confirmed. The most notable clarification provided by this study was the ploidy level of M. sieboldii ‘Colossus’, long thought to be hexaploid, yet multiple accessions from multiple sources were found to be diploid. This revelation, coupled with the discovery that M. ‘Sweet Summer’ is not a tetraploid hybrid, sheds light on the reason a cross between M. sieboldii ‘Colossus’ and M. ‘Sweet Summer’ (genome size documented in Table 2) so closely resembles M. grandiflora. Instead of a 6x × 4x cross that should have resulted in 5x hybrid with more intermediate characteristics, this was really a 2x × 6x cross heavily favoring the higher ploidy level of M. grandiflora. Another most interesting discovery was a cytochimera (tissue composed of cells with differing ploidy levels) of M. grandiflora ‘Little Gem’, created by Bob Head of Seneca, SC, by treating young rooted cuttings with oryzalin. The specimen was induced 10 years prior, and 55% of the cells in the examined tissue had remained dodecaploid (2n=12x=228). Multiple accessions of M. cylindrica (8x) and M. stellata (4x) from the Holden Arboretum were also confirmed as induced polyploids. In order to demonstrate the reliability of flow cytometry as a means to discern ploidy level, standard cytology was performed on a seedling of uncertain parentage. Actively growing root tips of container grown seedlings of putative octaploid M. cylindrica were collected at midday and placed in the mitotic inhibitor, 8-hydroxyquinoline for 2 h at 5 °C in dark conditions. The source of this seed was the Holden Arboretum via the Seed Counter of the Magnolia Society International. They were then transferred to a fixative solution of 3 parts 95% ethanol: 1 part glacial acetic acid (v/v) for 24 h, while remaining at 5 °C in dark conditions. Tissue was excised from just behind the root tip and placed in 12N HCl for 10 s. Squashes were prepared with a small amount of this tissue and a drop of modified Fuelgen stain on a slide with a cover slip. A chromosome count of one of these seedlings, SCC 2009-004, identified approximately 133 chromosomes (2n=7x=133) (Fig. 5), in close agreement with genome size data (14.92 pg) which was determined to be approximately 7x (6.7x). This supports the 36


Issue 90 assertion of Charles Tubesing (in MSI Seed Counter information) that the octoploids could have outcrossed with other magnolias with lower ploidy levels from their collections. Conclusion For me, this study has painted an abstract picture of the dance that takes place when gametes from Magnolias meet. Within species the match is so perfect that little or no genetic information is lost or gained that would lead to significant variation in genome size. The partners are well acquainted, the dance is well rehearsed, no toes are stepped on, and the performance is flawless. Yet, we have learned that Magnolia species may dance with different partners. Though they may have been separated by mountains, plains, or oceans, and eons of time, there is an affinity that still exists. The  harmony of the genetic  sequences  rings Figure 5: Photomicrograph of a root tip cell of Magnolia like a musical SCC 2009-004 in early metaphase, with approximately composition. Therefore, 133 chromosomes. Maternal parent Magnolia cylindrica the tune is familiar, and (2n=8x=152), paternal parent unknown, but likely though the partners may (2n=6x=114), resulting in a plant that is 7x stumble, the jubilation of the reunion often shines through in the dance. For breeders, the revised taxonomy by Figlar and Nooteboom (2004), along with molecular data presented by Azuma et al. (1999, 2000, 2001) and Kim et al. (2001), provides a greater understanding of the relatedness and potential for interspecific hybridizations among closely allied species that is often supported empirically in Table 3 of this paper. Yet, development of progeny from hybrids, beyond an F1 generation, requires genome/ chromosomal compatibility for meiosis to function properly. Thus, it is reasonable to expect that the greater the difference in genome size among parental species, the less likely hybrid progeny will be fertile. The results of this study have provided data on genome sizes and ploidy levels of Magnolia, confirmation of hybrids and induced polyploids, comparison of methods for determining genome size, and insights into reproductive biology that will help facilitate the development of improved hybrids in the future. If plants are developed with the inspiration of sound science 37


Magnolia and a creative eye, they will grace gardens beyond the life of the breeder, just like the melody of a classic song can transcend generations. Below is some of the sheet music, let us continue the song and dance. Table 1. Summary of means and ranges for 2C, holoploid genome size (pg) and 1Cx monoploid genome size (pg) of Magnolia spp. grouped by section and ploidy level. Ploidy level z Classification

2n = 2x = 38

2n = 4x = 76

2n = 6x = 114

2C = 3.80xEw

Nv

2C = 11.18 C

Subgenus Magnolia Section Magnolia (5/41y)

Section Gwillimia (4/6)

(3.43 - 4.40) u

(10.83 - 11.86)

1CX = 1.90t

1CX = 1.86

(1.72 - 2.20) s

(1.81 - 1.98)

2C = 5.32 A

N

N

N

N

N

N

N

N

(5.10 - 5.63) 1CX = 2.66 (2.41 - 2.82) Section Rhytidospermum (5/18)

2C = 4.27 CD (3.66 - 4.69) 1CX = 2.14 (1.83 - 2.35)

Section Manglietia (10/17)

2C = 4.87 B (4.65 - 5.25) 1CX = 2.44 (2.33 - 2.63)

Section Macrophylla (1/5)

2C = 4.57 BC (4.41 - 4.87) 1CX = 2.28 (2.21 - 2.44)

38


Issue 90 Section Auriculata (1/3)

2C = 3.83 E

N

N

N

N

2C = 4.05 DE

2C = 8.56 A

2C = 12.68 A

(3.84 - 4.26)

(8.08 - 9.34)

(11.49 - 13.47)

1CX = 2.02

1CX = 2.14

1CX = 2.11

(1.92 - 2.13)

(2.02 - 2.34)

(1.92 - 2.25)

2C = 4.56 BC

N

N

N

2C = 11.93 B

(3.74 - 3.96) 1CX = 1.94 (1.87 - 1.98) Section Kmeria (1/1)

2C = 5.51 A (5.51 - 5.51) 1CX = 2.76 (2.76 - 2.76)

Subgenus Yulania Section Yulania (14/43)

Section Michelia (17/31)

(4.23 - 4.92) 1CX = 2.28 (2.11 - 2.46) Subgenus Gynopodium

Section Gynopodium (2/3)

N

(11.57 - 12.50) 1CX = 1.99 (1.93 - 2.08) Section Manglietiastrum (1/1)

2C = 4.21 D

N

N

N

N

(4.21 - 4.21) 1CX = 2.11 (2.11 - 2.11) Genus Liriodendron (2/2)

39

2C = 3.41 F


1CX = 2.11

Magnolia Genus Liriodendron (2/2)

(2.11 - 2.11) 2C = 3.41 F

N

N

(3.35 - 3.47) 1CX = 1.71 (1.68 - 1.74)

z

Taxa assigned to given ploidy level onestimated estimated genome sizes in agreement with z Taxa assigned to given ploidy levelbased based on genome sizes and in and agreement with

published chromosome counts,ififavailable. available. published chromosome counts, y

Numbers in parentheses, following classifications, indicate the number of species Numbers in parentheses, following classifications, indicate the number of species

y

sampled, and the total number of taxa within those species sampled. sampled, and the total number of taxa within those species sampled.

x

Relative 2C genome sizes (pg) were determined using 4’,6-diamidino-2-phenylindole as the Relative 2C genome sizes (pg) were determined using 4’,6-diamidino-2-phenylindole as the

x

flourochrome stain.

flourochrome stain. w

Letters following Relative 2C genome sizes, within a column, are significantly different,

using the Waller Procedure(Proc GLM, SAS 9.1; SAS Cary, NC) for w Letters following Relative 2C genome sizes, version within a column, areInstitute, significantly different, using the Waller GLM, SAS version 9.1; SAS Institute, Cary, NC) for means separation, at PProcedure(Proc < 0.05. means separation, at P < 0.05.

N = No genome size reported; indicates given ploidy level was not reported or observed in this

v

section.

u

Values represent ranges of 2C genome size for all Magnolia spp. sampled in each section.

t

Relative 1Cx mean genome sizes (pg) were calculated as: (2C mean / ploidy level).

s

Values represent ranges of 1CX genome size means for all Magnolia spp. sampled in each section.

40


Issue 90 Table 2. Relative genome size (pg) and estimated ploidy level for a diverse collection of Magnoliaceae representing 62 species. Mean

Mean relative

Relative 2C

1Cx

genome size

genome size by

Ploidy

species (pg) y

level (x)

1.86

2

11.22

1.87

6

guatamalensis

4.37

2.19

2

sharpii

4.40

2.20

2

tamaulipana

11.28

1.88

6

coco

4.83

2.42

2

delavayii

5.28

2.64

2

hodgsonii

5.47

2.73

2

liliifera

5.63

2.82

2

3.97

1.99

2

4.01

2.00

2

3.72

1.86

2

Taxa

Cultivar/selection

(pg) z

Subgenus Magnolia Section Magnolia virginiana var. virginiana

including

3.72

R14-397 (thought to be tetraploid) virginiana var. australis grandiflora

3.73 including

‘Charles Dickens’ (suggested hybrid w/ macrophylla)

'Griffin' (suggested hybrid w/ virginiana) ‘Riegel’ (suggested hybrid w/ virginiana) ‘Sweet Summer’ (suggested hybrid w/ virginiana)

Section Gwillimia Subsection Gwillimia

Subsection Blumiana

Section Rhytidospermum Subsection Rhytidospermum obovata (hypoleuca) officinalis var. officinalis officinalis var. biloba

41


Section Rhytidospermum Subsection Rhytidospermum

Magnolia

obovata (hypoleuca)

3.97

1.99

2

officinalis var. officinalis

4.01

2.00

2

officinalis var. biloba

3.72

1.86

2

rostrata

4.69

2.35

2

tripetala

4.00

2.00

2

4.50

2.25

2

aromatica

5.15

2.58

2

changhungtana (pachyphylla)

4.69

2.35

2

conifera var. chingii

4.87

2.34

2

fordiana

4.81

2.41

2

garrettii

5.25

2.63

2

hookeri

4.82

2.41

2

insignis

4.94

2.47

2

kwangtungensis (moto)

4.65

2.33

2

ovoidea

5.02

2.51

2

yuyuanensis

4.74

2.37

2

macrophylla var. macrophylla

4.56

2.28

2

macrophylla var. ashei

4.52

2.26

2

macrophylla var. dealbata

4.87

2.44

2

fraseri var. fraseri

3.94

1.97

2

fraseri var. pyramidata

3.74

1.87

2

5.51

2.76

2

Subsection Oyama sieboldii

including â&#x20AC;&#x2DC;Colossusâ&#x20AC;&#x2122;

Section Manglietia

Section Macrophylla

Section Auriculata

Section Kmeria thailandica Subgenus Yulania Section Yulania Subsection Yulania amoena

4.26

2.13

2

biondii

4.12

2.06

2

campbellii

12.54

2.09

6

8.92

2.23

4

13.12

2.19

6

cylindrica dawsoniana

42


amoena

4.26

2.13

2

biondii

4.12

2.06

2

campbellii

12.54

2.09

6

cylindrica

8.92

2.23

4

dawsoniana

13.12

2.19

6

denudata

13.26

2.21

6

kobus

4.04

2.02

2

liliiflora

9.34

2.28

4

sargentiana

11.49

1.92

6

sprengeri

12.66

2.11

6

salicifolia

3.91

1.96

2

3.94

1.97

2

4.16

2.08

2

acuminata

8.24

2.06

4

acuminata var. subcordata

8.27

2.07

4

4.40

2.19

2

stellata

including

Issue 90

‘Two Stones’ (reported tetraploid) zenii Subsection Tulipastrum

Section Michelia cavaleriei var. platypetala

champaca

4.74

2.37

2

chapensis

4.92

2.46

2

doltsopa

4.52

2.26

2

ernestii

4.50

2.25

2

figo var. figo

4.58

2.29

2

figo var. skinneriana

4.48

2.24

2

figo var. crassipes

4.71

2.36

2

floribunda

4.51

2.26

2

foveolata var. foveolata ‘Shibamichi’

4.23

2.12

2

foveolata var. cinerascens

4.42

2.21

2

fulva var. calcicola

4.61

2.31

2

laevifolia

4.56

2.28

2

lanuginosa

4.80

2.40

2

maudiae

4.56

2.28

2

martini

4.75

2.38

2

odora

4.54

2.27

2

4.49

2.25

2

4.53

2.27

2

shiluensis sirindhorniae

43


maudiae

4.56

2.28

2

martini

4.75

2.38

2

odora

4.54

2.27

2

shiluensis

4.49

2.25

2

sirindhorniae

4.53

2.27

2

11.54

1.93

6

12.50

2.08

6

4.21

2.11

2

chinensis

3.47

1.74

2

tulipifera

3.35

1.68

2

Magnolia

Subgenus Gynopodium Section Gynopodium lotungensis yunnanensis

Vietnam origin

Section Manglietiastrum sinica Genus Liriodendron

Genome sizes were determined using 4â&#x20AC;&#x2122;,6-diamidino-2-phenylindole as the flourochrome stain. Values are means of

z

multiple samples, and often from multiple cultivars, accessions or sources.

1CX values were calculated as: [(2C value / ploidy level)

y

44


Issue 90 Table 3. Relative genome size (pg) and estimated ploidy level for interspecific hybrids of Magnolia arranged by reported parentage ploidy levels. Reported parentage

Cultivar/selection

Mean

Weighted 1CX

Reported

Estimated ploidy

Relative 2C

Genome size

parental

level (x)w

Genome

(pg)

y

size (pg)z

Ploidy levels (x)x

Subgenus Magnolia Intraploid Hybrids 2n=2x=38 insignis × virginiana

'Katie-O'

macrophylla × tripetala obovata × virginiana

'Nimbus'

4.30

2.15

2×2

2

3.68

2.12

2×2

2

3.79

1.93

2×2

2

officinalis × tripetala

3.96

1.95

2×2

2

sieboldii 'Colossus' × insignis

4.60

2.37

2×2

2

sieboldii 'Colossus' × insignis sieboldii 'Genesis' × virginiana

R10-24

×thompsoniana (=virginiana × tripetala)

4.63

2.37

2×2

2

4.06

2.06

2×2

2

3.95

1.93

2×2

2

'Silk Road' ((tripetala × obovata) × tripetala)) × insignis

4.35

2.23

2×2

2

yuyuanensis × insignis

4.53

2.43

2×2

2

4.67

2.32

2×2

2

4.41

2.12

2×2

2

4.23

2.17

2×2

2

5.62

1.87

4×2

3

7.52

1.87

6×2

4

8.53

2.02

2×6

4

yuyuanensis × sieboldii

104/1

yuyuanensis × virginiana virginiana ’Havener’ × insignis (Red Form)

111/7

Interploid Hybrids 2n=3x=57 (grandiflora × virginiana) × virginiana

2n=4x=76 grandiflora × virginiana

'Maryland'

insignis × grandiflora 'Kay Parris' sieboldii 'Colossus' × grandiflora 'Bracken’s Brown Beauty’

7.87

1.97

2×6

4

sieboldii 'Colossus' × grandiflora 'Kay Parris'

8.23

1.97

2×6

4

sieboldii 'Colossus' × 'Sweet Summer'

8.02

1.97

2×6

4

sieboldii 'Pride of Norway' × 'Sweet Summer'

7.99

1.97

2×6

4

9.00

1.87

4×6

5

2n=5x=95 'Maryland' (grandiflora × virginiana) ×

(Maryland

grandiflora

Seedling)

Subgenus Yulania Intraploid Hybrids 2n=2x=38

45


sieboldii 'Pride of Norway' × 'Sweet Summer'

7.99

1.97

2×6

4

9.00

1.87

4×6

5

1.99

2×2

2n=5x=95

Magnolia

'Maryland' (grandiflora × virginiana) ×

(Maryland

grandiflora

Seedling)

Subgenus Yulania Intraploid Hybrids 2n=2x=38 'Wada's ×kewensis (=kobus × salicifolia) ×loebneri (=kobus × stellata)

Memory'

3.83

2

‘Donna’

5.86

2.00

2×2

3

'Pink Superstar'

4.02

2.00

2×2

2

4.00

2.00

2×2

2

'Leonard Messel' 'Mag's Pirouette'

3.97

2.00

2×2

2

'Merril'

3.86

2.00

2×2

2

'Spring Snow’

3.86

2.00

2×2

2

'Wildcat'

3.98

2.00

2×2

2

4.81

2.28

2×2

2

4.46

2.28

2×2

2

4.53

2.27

2×2

2

×alba (=champaca × montana) laevifolia × figo

(Clifford Parks)

×foggii (=figo × doltsopa)

2n=4x=76 acuminata 'Busey' × acuminata sub. 'Miss Honeybee'

'Miranja'

18.25

2.10

4×4

~8.6

liliiflora 'O'Neill' × kobus 'Norman Gould'

‘Roseanne’

8.53

2.15

4×4

4

'Solar Flair'

8.19

2.13

4×4

4

'Sunburst'

8.07

2.13

4×4

4

×brooklynensis 'Woodsman' × 'Gold Star' (acuminata ‘Miss Honeybee’ × stellata) ×brooklynensis 'Woodsman' ×'Gold Star' (acuminata ‘Miss Honeybee’ × stellata) ×brooklynensis ‘Woodsman’ בGold Star’ (acuminata ‘Miss Honeybee’ × stellata)

'Tranquility'

8.15

2.13

4×4

4

×brooklynensis (=acuminata × liliiflora)

'Woodsman'

8.21

2.17

4×4

4

2n=6x=114 denudata × sprengeri 'Diva'

'Legacy'

13.11

2.16

6×6

6

sargentii var. robusta × campbellii

'Hawk'

12.67

2.01

6×6

6

12.96

2.15

6×6

6

×veitchii (=campbellii × denudata) Interploid Hybrids cylindrica × ×veitchii 'Peter Veitch'

'Albatross'

11.14

2.18

4×6

5

×soulangeana (=denudata × liliiflora)

'Alexandrina'

10.70

2.24

6×4

5

×soulangeana (=denudata × liliiflora)

'Andre Leroy'

14.60

2.24

? ×?

~6.5

cylindrica × denudata 'Sawada's Pink'

'Angelica'

10.83

2.22

4×6

5

stellata × liliiflora 'Nigra'

'Ann'

6.28

2.18

2×4

3

liliiflora × cambellii 'Lanarth'

'Apollo'

11.02

2.17

4×6

5

46


cylindrica × ×veitchii 'Peter Veitch'

'Albatross'

×soulangeana (=denudata × liliiflora) ×soulangeana (=denudata × liliiflora)

11.14

2.18

4×6

5

'Alexandrina'

10.70

2.24

6×4

5

'Andre Leroy'

14.60

2.24

? ×?

~6.5

cylindrica × denudata 'Sawada's Pink'

'Angelica'

10.83

2.22

4×6

5

stellata × liliiflora 'Nigra'

'Ann'

6.28

2.18

2×4

3

liliiflora × cambellii 'Lanarth'

'Apollo'

11.02

2.17

4×6

5

Issue 90

'Vulcan' (campbellii 'Lanarth' × liliiflora) × ×soulangeana 'Lennei'

ArborTree Select

16.97

2.21

5×~8

~7.7

'Athene'

14.96

2.14

~7.6×6

~7

(campbellii ‘Lanarth’ × sargentiana)

'Atlas'

12.82

2.14

~8×6

~6

stellata 'Rosea' × liliiflora 'Nigra'

'Betty'

6.61

2.18

2×4

3

×soulangeana 'Lennei Alba' × 'Mark Jury' (campbellii ‘Lanarth’ × sargentiana) ×soulangeana 'Lennei' × 'Mark Jury'

‘Yellow Bird' (acuminata × ×brooklynensis ‘Evamaria’) × 'Caerhays Belle' (sargentiana × sprengeri ‘Diva’)

'Blushing Belle'

10.32

2.11

4×6

5

acuminata × denudata 'Sawada's Cream'

'Butterflies'

10.71

2.15

4×6

5

‘Legend’ × ‘Butterflies’

'Coral Lake'

12.09

2.15

5×5

~5.6

×veitchii × ×soulangeana

'David Clulow'

16.75

2.19

6×?

~7.6

(×soulangeana ‘Lennei Alba’ × ×veitchii)

'Daybreak'

10.71

2.20

4×~6.9

~4.9

acuminata × denudata

'Elizabeth'

10.59

2.15

4×6

5

denudata × stellata 'Waterlily'

'Emma Cook'

10.26

2.15

6×2

~4.8

'Eskimo'

9.99

2.14

4×~8

~4.6

'Felicity'

10.75

2.18

6×5

~4.9

×brooklynensis 'Woodsman' × 'Tina Durio'

kobus 'Norman Gould' × ×soulangeana 'Lennei’ sprengeri 'Diva' × ×soulangeana 'Wada’s Picture' ×soulangeana 'Deep Purple Dream’ × 'Paul Cook'

'Frank's Masterpiece'

14.66

2.19

?×6

~6.7

×soulangeana (=denudata × liliiflora)

'Fukuju'

19.02

2.24

?×?

~8.5

liliiflora 'Nigra’ × sprengeri 'Diva'

'Galaxy'

10.45

2.18

4×6

5

acuminata var. sub. 'Miss Honeybee' ×

'Gold Finch'

10.81

2.15

4×6

5.0

acuminata × denudata

'Golden Sun'

13.59

2.15

4×6

~6.3

acuminata × stellata

‘Gold Star’

8.22

2.06

4×2

4

×soulangeana (=denudata × liliiflora)

'Grace McDade'

17.35

2.24

?×?

~7.8

'Green Snow'

11.47

2.20

(4×~8)×5

~5.2

'Hot Flash'

8.43

2.15

4×5

~3.9

denudata 'Sawada's Cream'

(×brooklynensis ‘Woodsman’ × ×soulangeana 'Lennei') × 'Elizabeth' (acuminata × denudata) ×brooklynensis 'Woodsman' × 'Elizabeth' (acuminata × denudata) 'Mark Jury' (campbellii ‘Lanarth’ × sargentiana) × ×soulangeana 'Lennei'

'Iolanthe'

13.62

2.14

6×~8

~6.4

acuminata × denudata

'Ivory Chalice'

10.76

2.17

4×6

5

×soulangeana × ×veitchii

'Jon Jon'

15.16

2.19

?×6

~6.9

×loebneri ‘Encore’ × ×soulangeana

47


×brooklynensis 'Woodsman' × 'Elizabeth' (acuminata × denudata)

'Hot Flash'

8.43

2.15

4×5

~3.9

sargentiana) × ×soulangeana 'Lennei'

'Iolanthe'

13.62

2.14

6×~8

~6.4

acuminata × denudata

'Ivory Chalice'

10.76

2.17

4×6

5

×soulangeana × ×veitchii

'Jon Jon'

15.16

2.19

?×6

~6.9

‘Alexandrina’

Kehr Seedling

10.92

2.17

2×~5

~5

acuminata × denudata

'Legend'

10.77

2.15

4×6

5

×soulangeana (=denudata × liliiflora)

'Lennei'

17.89

2.24

?×?

~8

×soulangeana (=denudata × liliiflora)

'Lennei Alba'

16.91

2.24

?×?

~7.6

Pink'

'Limelight'

14.23

2.18

4×?

~6.5

acuminata × (acuminata × denudata)

'Lois'

14.61

2.10

4×5

~7.0

×soulangeana × ×veitchii

'Manchu Fan'

14.86

2.19

?×6

~6.8

(liliiflora × cylindrica) × ×soulangeana 'Ruby'

'March till Frost'

12.89

2.25

4×?

~5.7

‘Diva’)

'Millie Gaylon'

14.20

2.21

~8×(?×6)

~6.4

stellata × liliiflora

'Orchid'

2.18

2×4

3

acuminata × ×veitchii 'Peter Veitch'

'Pastel Beauty'

10.12

2.13

4×6

5

acuminata × sprengeri 'Diva'

'Peachy'

10.11

2.11

4×6

5

×soulangeana (=denudata × liliiflora)

'Pickard's Firefly'

17.06

2.24

?×?

~7.6

liliiflora 'Reflorescens' × stellata 'Rubra'

'Pinkie'

6.47

2.18

4×2

3

liliiflora × ×soulangeana

'Purple Prince

10.91

2.26

4×?

~4.8

liliiflora 'Nigra' × stellata

'Randy'

6.44

2.18

4×2

3

'Wada’s Picture' × sprengeri 'Diva')

'Red Baron'

13.19

2.14

4×(?×6)

~6.2

liliiflora × ×veitchii

'Royal Crown'

10.58

2.20

4×6

5

liliiflora × ×veitchii

'Sayonara'

14.82

2.20

4×6

~6.7

'Serene'

10.59

2.12

4×6

5

liliiflora)

'Shiraz'

12.76

2.19

6×5

~5.8

liliiflora 'Nigra’ × sprengeri 'Diva'

'Spectrum'

11.58

2.18

4×6

5

campbellii × liliiflora

'Star Wars'

10.53

2.17

6×4

5

acuminata × denudata

'Sunray'

10.22

2.17

4×6

5

'Mark Jury' (campbellii ‘Lanarth’ × Magnolia

×loebneri ‘Encore’ × ×soulangeana

acuminata var. subcordata × ×soulangeana 'Big

×soulangeana 'Lennei' × 'Paul Cook' (×soulangeana ‘Lennei’ seedling × sprengeri

6.44

acuminata × 'Big Dude' (×soulangeana

liliiflora × 'Mark Jury' (campbellii ‘Lanarth’ × sargentiana) denudata × 'Vulcan' (campbellii 'Lanarth' ×

×brooklynensis 'Woodsman' × 'Elizabeth' (acuminata × denudata)

'Sunsation'

14.73

2.18

4×5

~6.8

liliiflora × stellata 'Rosea'

'Susan'

6.58

2.18

4×2

3

×soulangeana 'Lennei Alba' × ×veitchii

'Tina Durio'

15.23

2.20

~7.6×6

~6.9

×veitchii × ×soulangeana 'Rustica Rubra'

'Todd Gresham'

14.75

2.19

6×?

~6.7

campbellii 'Lanarth' × liliiflora hybrid

'Vulcan'

10.54

2.17

6×4

5

14.43

2.18

4×5

~6.6

48

acuminata var. subcordata × ×soulangeana 'Alexandrina'

'Yellow Lantern'


(acuminata × denudata)

'Sunsation'

14.73

2.18

4×5

~6.8

liliiflora × stellata 'Rosea'

'Susan'

6.58

2.18

4×2

3

×soulangeana 'Lennei Alba' × ×veitchii

'Tina Durio'

15.23

2.20

~7.6×6

~6.9

×veitchii × ×soulangeana 'Rustica Rubra'

'Todd Gresham'

14.75

2.19

6×?

~6.7

campbellii 'Lanarth' × liliiflora hybrid

'Vulcan'

10.54

2.17

6×4

5

'Alexandrina'

'Yellow Lantern'

14.43

2.18

4×5

~6.6

acuminata × denudata

'Yellow Sea'

8.68

2.17

4×6

4

'Zeal'

10.15

2.17

5×6

~4.6

6.16

2.16

4×2

3

12.34

2.13

5×6

~5.8

Issue 90

acuminata var. subcordata × ×soulangeana

'Pegasus' (cylindrica × denudata) × campbellii 'Darjeeling' acuminata × figo ‘Galaxy' (liliiflora 'Nigra’ × sprengeri 'Diva') × campbellii var. Mollicomata ×veitchii 'Isca' × liliiflora

10.84

2.13

6×4

5

cylindrica hybrid (Polly Hill)

13.35

2.23

4×?

6.0

14.92

2.23

8×?

~6.7

15.21

2.23

8×?

~6.8

cylindrica hybrid (Holden via MSI seed counter) cylindrica hybrid (Holden via MSI seed counter)

z

Genome sizes were determined using 4’,6-diamidino-2-phenylindole as the flourochrome stain. Values are means of multiple

samples.

y

Weighted 1CX values were calculated as: [(1CX value of the female parent × ploidy level of the female parent/2) + (1CX value of

the male parent × ploidy level of the male parent/2)]/[(ploidy level of the female parent + ploidy level of the male parent)/2] . When the 1CX was not known for the exact parent, then an average for the parental species or section was used.

x

Reported parental ploidy levels.

w

Estimated ploidy levels were calculated as: 2C genome size / weighted 1CX value. If both parent species had even ploidy

levels, then ploidy levels of the progeny were rounded to the nearest whole numbers if supported by an appropriate relative genome size. If either parent had an odd ploidy level, then ploidy levels of the progeny were rounded to the nearest 0.01 to reflect apparent aneuploidy.

49


Magnolia Table 4. Relative genome sizes (pg) and estimated ploidy levels of artificially induced polyploid Magnolia spp. Estimated

Taxa

Relative 2C Mean

Ploidy level

genome size (pg) z

(x)y

cylindrica

17.3

8

11.11

6

21.80

12

7.79

4

8.2

4

grandiflora ‘Little Gem’ (cytochimera)

kobus ‘Norman Gould’ stellata

z

Genome sizes were determined using 4’,6-diamidino-2-phenylindole as

the flourochrome stain. Values are means of multiple samples.

y

Estimated ploidy levels were calculated as: 2C genome size / 1CX value (2.23 for M. cylindrica, 1.87 for M.

grandiflora, 2.02 for M. kobus, and 1.97 pg for M. stellata ) and rounded to the closest whole number.

Acknowlegements In addition to the co-authors of the originally published paper, I would like to thank Tom Eaker, Nathan Lynch, Joel Mowrey, Jeremy Smith, and Darren Touchell of North Carolina State University, Mills River, NC, for their technical assistance throughout the study. Literature Cited Azuma, H., L.B. Thien, and S. Kawano. 1999. Molecular phylogeny of Magnolia (Magnoliaceae) inferred from cpDNA sequences and evolutionary divergence of floral scents. J. Plant Res. 112:291–306. Azuma, H., L.B. Thien, and S. Kawano. 2000. Molecular phylogeny of Magnolia based on chloroplast DNA sequence data and floral scent chemistry. Proc. Intl. Symp. Family Magnoliaceae 219-227. Azuma, H., J.G. García-Franco, V. Rico-Gray, and L.B. Thien. 2001. Molecular phylogeny of the Magnoliaceae: The biogeography of tropical and temperate disjunctions. Amer. J. Bot. 88:2275–2285. 50


Issue 90 Callaway, D.J. 1994. The World of Magnolias. Portland, OR:Timber Press. Chen, Z., X. Huang, R. Wang, and S. Chen. 2000. Chromosome data of Magnoliaceae. Proc. Intl.  Symp. Family Magnoliaceae. 192-201. Doležel, J., J. Greilhuber, and J. Suda. 2007. Flow cytometry with plant cells: Analysis of genes, chromosomes and genomes.  Wiley- VCH, Weinheim. Germany. Figlar, R.B. and H.P. Nooteboom 2004. Notes on Magnoliaceae IV. Blumea 49:1-14. Greilhuber, J., E.M. Temsch, and J.C.M. Loureiro. 2007. Nuclear DNA content measurement, p. 67-101. In: J. Doležel, J. Greilhuber, and J. Suda (eds.). Flow cytometry with plant cells: Analysis of genes, chromosomes and genomes. Wiley- VCH, Weinheim. Germany. Jones, J.R., T.G. Ranney, N.P. Lynch, and S.L. Krebs. 2007. Ploidy levels and genome sizes of diverse species, hybrids, and cultivars of Rhododendron L. J. Amer. Rhododendron Soc. 61:220-227. Kehr, A.E. 1985. Inducing polyploidy in magnolias.  J. Amer. Magnolia Soc.  20:6-9. Kim, S., C. Park, Y. Kim, and Y. Suh. 2001. Phylogenetic relationships in family Magnoliaceae inferred from NDHF sequences. Amer. J. Bot. 88:717–728. McDaniel, J.C. 1968. Magnolia hybrids and selections. Proc. Central States For. Tree Improvement Conf. 6:6-12. Parris, J.K., T.G. Ranney, H.T. Knap, and W.V. Baird. 2010. Ploidy Levels, Relative Genome Sizes, and Base Pair Composition in Magnolia. J. Amer. Soc. Hort. Sci., 135: 533-547. Santamour Jr., F.S. 1970. Cytology of magnolia hybrids II. M. ×soulangiana Hybrids. Morris Arboretum Bul. 21:58-61. Treseder, N.G. 1978. Magnolias. Boston: Faber and Faber.

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Magnolia

Exploring in Vietnam

Editor’s note: Modern-day plant explorers, Scott McMahan and Dan Hinkley, provide separate reports on their recent plant exploration trips to northern Vietnam. Dan describes the results of various sites and dates of Vietnamese ventures, while Scott focuses on their joint exploration in 2010 to the Five Finger Mountains.

Magnolias in Vietnam

Dan Hinkley

During the past twenty-five years I have had the opportunity to examine numerous Magnolia taxa in situ: M. sargentiana, M. delavayi, M. floribunda and M. wilsoni in China, M. salicifolia and M. obovata in Japan; M. sieboldii and M. compressa in Korea; M. campbellii in Bhutan and E. Nepal. These encounters, though exciting, were only occasional incidentals to the mostly deciduous flora of each country and in no way prepared me for the opulence of the Magnoliaceous inventory of northern Vietnam. Beginning in 1999, I have had the opportunity to visit numerous sites in Vietnam a total of seven times. Slowly but steadily, with the gracious help of Dick Figlar, I have become more comfortable in determining the identity of the approximately ten species of Magnolia that occur in this region. It should be noted that in untrammeled areas of Vietnam; i.e., with no significant deforestation, the seed of numerous Magnolias—sometimes with their associated receptacles and sometimes not— are collected on the ground from specimens towering high overhead. Though these are often parasitized, for those that do successfully transition from the collection bag through USDA inspection to a potted plant, numerous years await before certain identification can be made. My collections of Magnolia sp. HWJ 99461 (Hinkley, Wynn-Jones) were made during our first ascent of Fan Si Pan near Sa Pa in 1999. The highest mountain in Indochina, it rises to 10,312ft, with the lower slopes seriously degraded by human activity and the upper slopes an unclimactic monostand of bamboo. The Goldilocks zone is a dense evergreen jungle comprised chiefly of Theaceae, Lauraceae, Araliaceae, Hamamelidaceae and, of course, Magnoliaceae. M. grandis, a rare find in Vietnam, shown proudly by two guides 52


Issue 90 In 1999, prior to the dedication of this area as a national park and subsequent development of basic tourist facilities, the climb up the eastern side of the mountain from the town of Sa Pa was a minimum three-day round trip. It was while approaching our first bit of forest on an upper ridge at 7,350ft that we came upon an exposed specimen of Magnolia laden with ripened seed in large, oblong, upright cones. Three of five seedlings from this collection have blossomed in my zone 8 garden, showing significant variation in color, from slight pink to a handsome rose. Dick Figlar has tentatively identified them as M. insignis. On the same mountain in 2008, but on the northern side outside of the park perimeter, beginning from the village of Seo Mi Ty, perennial traveling companions Scott McMahan and Ozzie Johnson and I, along with a legion of guides and porters, trekked along a river drainage at mod- Magnolia aff. insignis erate elevations before climbing up onto the HWJ 99621 densely forested mountain slopes. Along this river grew a staggering diversity of Magnolias with apocarpus species (M. martini, M. foveolata and M. fulva) growing adjacent to those with cylindrical and cone-shaped fruit (respectively, M. cathcartii and M. insignis; M. sapaensis and M. grandis). Finding the latter is considered to be a new record for Vietnam, as it has been known only to southern Yunnan prior to this. Besides the Magnolias, also present of note were Acer, Styrax, Illicium, Mahonia, Edgeworthia and Stauntonia. In 2006, 2008 and 2010 we traveled to the northwest of Lao Cai to an area of moderate elevation on the Chinese frontier known as Y Ty. Attesting to how close to the border we actually were on our last trip, our campsite was visited the first night by border police, who spent considerable time perusing our passports. This is Rusty indumentum on underside of M. foveolata leaves. 53


Magnolia a remarkable area with a rich aggregation of familiar genera, including Acer, Rhodoleia, Loropetalum, Schefflera and Magnolia, though the local tribal minorities are still cutting the forests for firewood at an alarming rate. Most memorable here were stunning specimens of M. foveolata, with leaves undersurfaced in a rich rusty red indumentum. Fortunately, we were afforded the luxury of youthful and agile porters who would readily scale the trees barefoot to help collect seed. There are remarkable changes happening in Vietnam, in regard to its environmental ethos as well as the existence of tourist facilities throughout much of the country. In addition to its lovely and welcoming people and French-infused cuisine, there exists a superb inventory of plants readily witnessed if but with a bit of physical exertion. A specimen of M. sapaensis illustrates the unique attributes of this species: copperygolden pubescence on the buds only, and the rich green leaves are contrasted by glaucouswhite on their backsides.

Exploring in Five Finger Mountains,Vietnam

Scott McMahan

Last fall, I had the opportunity to travel back to the high mountains of northern Vietnam with my faithful traveling companions, Ozzie Johnson and Dan Hinkley. This was the second time we had botanized in these mountains together. Our main goal was to continue to try to explore remote areas in the Fan Xi Pan mountain A view of the Five Finger Mountains

54


Issue 90 range as well as do some snooping around in a new area or two in order to begin to test the hardiness of these Vietnamese plants in gardens both in the southeast as well as the Pacific Northwest. Outside of the Fan Xi Pan Mountains, one of the most interesting areas for temperate flora we explored was a group of mountains called the Five Finger Mountains. Hiking in this part of the world could almost be interchanged with the word â&#x20AC;&#x2DC;mountaineeringâ&#x20AC;&#x2122;. The mountains that create the border between China and Vietnam are rugged, steep jungles that are difficult at best to navigate, and hacking through them is the only way to make progress. This part of the trek began with our driver dropping us off at a turn in the road where the three of us, our trusted guides, Uoc and Ton, and three porters piled out. Since there are no real roads leading up into the mountains, other than rutted out pig trails used by motorbikes, our adventures in this region usually begin in this way. We started out by climbing up into the mountains on a dirt path that wound through some sort of a work camp and finally into the jungle. Along the way, we began to notice the change from cut-back trees and shrubs that were struggling to grow along the trail to majestic, broad-leaved evergreen tree outcroppings, which led the way to the dense canopy in the mountains. I began to realize that these huge trees in the distance were not oaks or maples such as we had seen at lower elevationsâ&#x20AC;Śthey were at least three different species of mature magnolias. What a feeling to be standing amongst groves of Asian magnolias that had been allowed to grow and mature! Our main method of germplasm collection is via seed. While most of the magnolias were not laden with ripe cones full of seed, we did make several significant collections in this area and were able to tentatively identify those species, thanks to Dick Figlar and digital photography. I began snapping photos and collecting not only seed, but also branch cuttings, which I could clearly photograph later and send to Dick. Before I left for my trip, I had received an in-depth tutorial on keying out evergreen species of magnolias from Dick in his garden. Because of this exercise, I was able to give him descriptive information about the buds, undersides of the foliage, Fellow plant explorer Dan Hinkley walking glossiness of the leaf, the presence toward groves of M. foveolata growing in a or absence of leaf scars, and other moist valley in the Five Finger Mountains. 55


Magnolia details. By exchanging emails and pictures, we usually had valid identification for our collections within 24 hours. In the areas we visited on this trip, Magnolia foveolata seemed to be the most widespread. We usually found this species growing in full sun, but the soil conditions ranged from fairly dry pastures to very wet, bog-like conditions. I would never have imagined that these huge trees would have grown so well with their roots completely submerged in water. The trees themselves were as diverse as the conditions they grew in. Some had beautiful golden indumentum on the undersides and some displayed fine silver hairs and some had none at all. Based on foliage alone, very ornamental selections of this harM. foveolata with ripe seed dy species could be made. As we continued onward up into the mountains, we came across an impressive Magnolia species growing happily by a river. Characterized by long, narrow leaves with short stipule scars along with prominent flower buds covered in golden indumentum held in the leaf axils, we wondered if it was M. floribunda. As far as we could tell, this was one of the only specimens of this particular taxon we encountered. Growing close by, we also found quite a few specimens of M. insignis, which has a wide natural distribution, from northeast India, Nepal and southern Sichuan in the north to northern Vietnam and Thailand in the south. While there are several hardy selections of M. insignis being grown in the US, M. insignis from this area unfortunately seem to be very tender. I was especially disappointed with the apparent lack of hardiness of M. insignis, as collections from previous trips to this region have yielded vigorous plants with hints of red pigment in the foliage, but north Georgia winters (zone 7) have proven to be too cold for them. At our highest elevation of Magnolia collection from this area (6,700ft), we discovered a very exciting and rare species known as Magnolia cathcartii. We had seen this species at lower elevations without fruit and while it did resemble something in Magnoliaceae, I decided that it more closely resembled something related to Ficus and continued on. Compared to other Magnolias in the area, this species has very small, glossy foliage completely free of indumentum. When we finally came upon a tree with fruit on it and could then positively identify it as a Magnolia, we collected the seed 56


Issue 90 and began taking pictures to send to Dick, hoping for quick identification. Little did I know, this species is easily identified by a very prominent midrib on the upper surface of the leaf. What a great find as this species is virtually non-existent in US gardens. I have now seen with my own eyes the amazing diversity of Magnoliaceae that occurs from southwestern China and into the mountains of northern Vietnam. In fact, of the six collecting trips I have made to Western China and Northern Vietnam, the trip we took in the fall of 2010 proved to me that much exploration still needs to be done in the mountains that create the border between these two countries. I would like to thank my friends Dick Figlar and Philippe de Spoelberch for their very generous support of my collecting efforts last fall. Without these sorts of collaborations with individuals, botanical institutions and serious plant societies, explorations and plant introductions of this sort would be impossible.

Glossy M. cathcartii leaves with prominent mid-rib

57


Magnolia

New cultivar registrations 2010-2011

Timothy M. Boland, Registrar, Magnolia Society International Executive Director, Polly Hill Arboretum The following two cultivars were submitted by William Forster, Dennison, Illinois, USA. Both trees grow just west of Charleston, Illinois (USDA zone 5b), in black prairie loam soil. Selected, named, and cultivated by Wesley Whiteside who received seeds from the late J.C. McDaniel of Champaign-Urbana, Illinois. The seed parent was Magnolia ×brooklynensis ‘Woodsman’; the pollen parent is unknown. The following two trees described below were selected out of a dozen seedlings that resulted from this cross. These magnolias prefer full sun and moisture-retentive soils. ‘Illini Gold’ (Magnolia xbrooklynensis ‘Woodsman’ x unknown taxon) The tree is described as a vigorous grower and at 26 years of age is estimated to have a height of 35ft (10.6m) and a width of 15ft (4.5m). The flowers were first observed in 1995 and are described as an excellent yellow and produced in large amounts. Typical bloom time is late April in southern Illinois. The tree shape and flowers are very similar to M. acuminata. ‘Illini Moonlight’ (Magnolia xbrooklynensis ‘Woodsman’ x unknown taxon) The tree is described as a vigorous grower and at 26 years of age is estimated to have a height of 35ft (10.6m) and a width of 15ft (4.5m). The flowers were first observed in 1995 and are described as medium yellow and smaller in size compared to ‘Illini Gold’. Typically in bloom in late April in southern Illinois, tree shape and flowers are very similar to M. acuminata.

58


Issue 90 Both trees are available from: Whitman Farms 3995 Gibson Road, NW Salem, Oregon, 97304 http://whitmanfarms.com Magnolia Store Piet Vergeldt Boomkwekerij bv Horsterdijk 103 5973 PM Lottum The Netherlands http://www.magnoliastore.com Registered by William Forster, Dennison, Illinois, USA

‘Simpson’s Hardy’ (Magnolia grandiflora) This tree has grown for over 60 years at the Simpson Nursery Company, Vincennes, Indiana, USA (USDA, zone 6a). It was originally purchased from an unknown source. Robert Simpson, the original proprietor of the nursery, had planted it as a Mother’s Day gift. The tree is considered unique for its hardiness, surviving -30°F (-34°C). It is described as pyramidal when grown in full sun, producing large white flowers 12in (30cm) in diameter. The foliage is heavy, dark green with good indumentum. At present time the tree is 65ft (20m) in height and 30ft (9m) in width. The tree has carried the unofficial name of ‘Simpson’ for a few years and was previously mentioned under this name in this journal, Issue 60, Summer 1996. However, according to Betsy Simpson, daughter of the late Robert Simpson, and current proprietor of the Simpson Nursery Company, they have always referred to it as ‘Simpson

59


Magnolia Hardy’ or ‘Simpson’s Hardy’. The current registration of this name attempts to stabilize its use in the nursery trade and capture the unique cold tolerance of this primarily southern species. It is recommended that the tree be purchased on its own roots to insure a hardy constitution, or at the very least, be grafted on rootstock known to be hardy in northern climates. The tree is available from: The Simpson Nursery Company 1504 Wheatland Rd PO Box 1216 Vincennes, IN 47591 info@simpsonnursery.com Rare Find Nursery 957 Patterson Road Jackson, NJ 08527 rarefindnursery.com support@rarefindnursery.com Pleasant Run Nursery PO Box 247 Allentown, NJ 08501 http://www.pleasantrunnursery.com pleasantrunnursery@verizon.net Original tree located at Simpson Nursery, Vincennes, Indiana, USA

Registered by William Forster, Dennison, Illinois, USA, on behalf of Betsy Simpson.

(photo by Sylvia Stanat)

‘After Elizabeth’ (Magnolia hybrid origin) Selected and named by Tom Krenitsky of Chapel Hill, North Carolina, USA. The tree was raised as a seedling of unknown progeny. First observed in the spring of 1990, it exhibits flowers similar to Magnolia ×soulangeana but with distinct markings (purplish-red) on the outer tepals. Magnolia expert Richard Figlar has suggested that it may be a backcross of Magnolia liliiflora with M. ×soulangeana. It flowers prolifically and over a 60


Issue 90 (photo by Sylvia Stanat)

three-week period. The originator noted its late March bloom (after frosts) as a positive attribute. It always followed the bloom of Magnolia â&#x20AC;&#x2DC;Elizabethâ&#x20AC;&#x2122; in his garden; thus, he decided upon the name designated here. Subsequently, it has been propagated by Camellia Forest Nursery in Chapel Hill, NC, and reportedly roots easily under mist and grows well in containerized production. The tree can be grown as a multi-stem or single stem tree in production. Currently, the original tree is 20ft. (6m) tall and has multiple trunks. The tree has been distributed in Europe in recent years and is available in the USA from: Camellia Forest Nursery 620 Hwy 54 West Chapel Hill, NC 27516 http://www.camforest.com/ CamelliaForest@gmail.com Registered by Tom Krenitsky of Chapel Hill, North Carolina, USA

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Magnolia

Specialists in full-standard Magnolias

w w w w.v ivaimasettisabino.it

MASETTI SABINO NURSERIES

S.S.A.

Via bassa della Vergine, 214/C - 51100 Pistoia - Italy Tel. +39 0573 380404 - Fax +39 0573 985028 info@vivaimasettisabino.it www.vivaimasettisabino.it

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Issue 90

The Research Foundation of the Magnolia Society The Magnolia Society Endowment Fund needs your support Please send your contributions to: The Research Foundation Fund 518 Parker Street Gibson, TN 38338 USA Contributions are tax deductible in the United States.

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Magnolia

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Issue 90

We offer more than 450 varieties of grafted magnolias. Among these are some of the latest hybrids and very rare selections of Magnolia species. Full stock list and availability as download or on request. Worldwide shipping â&#x20AC;&#x201C; international orders welcome. Visit our reworked website with many magnolia photos! EISENHUT NURSERIES CH 6575 San Nazzaro Switzerland Tel: +41 91 795 18 67 Fax: +41 91 795 30 29 Internet: www.eisenhut.ch e-mail: info@eisenhut.ch

HEASELANDS GARDEN 65


Magnolia

Broken Arrow Nursery 13 Broken Arrow Rd. Hamden, CT 06518

Growers of more than 50 different magnolias as well as countless other rare and unusual plants

Magnolia x ‘Daybreak’

www.brokenarrownursery.com Retail • Mail-order • Wholesale info@brokenarrownursery.com 203.288.1026 66


Issue 90

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Magnolia

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Magnolia Society International, Inc. Officers

Standing Committee Chairs

President Andrew Bunting 408 Vassar Avenue Swarthmore, PA 19081 abuntin1@swarthmore.edu

Registered Corporate Agent Karen Vallowe

Vice President Gary Knox University of Florida N. Florida Research and Education Center 155 Research Rd. Quincy, FL 32351

Research Dr. Paul Cappiello

Secretary Beth Edward 3000 Henneberry Road Jamesville, NY 13078 Treasurer Larry Langford 518 Parker Street Gibson, TN 38338 Editor Cheryl Doyle Kearns 102 Colonial Drive Youngsville, NC 27596 cherylkea1017@yahoo.com Acting Webmaster Beth Edward

Finance Larry Langford

Annual Meetings Chair Anita Figlar International Registrar of Magnolia Cultivars Timothy M. Boland tim@pollyhillarboretum.org Nominations Gary Knox Seed Counter Stefan P. Cover Awards and Honors Richard B. Figlar



MSI JOURNAL ISSUE 90