PlantIntel Vol. 3, Issue 1

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Pivoting for plants About this issue:

As the pandemic loomed a little more than a year ago and the Atlanta Botanical Garden closed its gates, the priority was clear: The safety of guests, staff and volunteers came first. What was less clear, however, was how the Garden’s mission “to develop and maintain plant collections for display, education, research, conservation and enjoyment” would continue. But clever, resourceful and creative staff found a way – in fact, many ways – around the myriad hurdles they would encounter throughout the year that followed. Sultry summer days weren’t meant for wearing hot protective masks, but Garden horticulturists persevered just the same. They were among several essential staffs that would be needed on site to continue operations, and strict social distancing and sanitation measures were taken to ensure their safety. As the pandemic stretched on, reduced travel for plant collecting and conservation field work would force managers to rethink projects as they worked from home. Dedicated volunteers, many of them seniors, would seemingly vanish, leaving horticulturists to take on their friends’ valued work. School field trips and in-school programs would come to a screeching halt as “virtual learning” became the buzz. Yet, during the two-month closure – and beyond – the Garden learned to pivot, even discovering some silver linings among the ominous clouds of the coronavirus. The Horticulture & Collections team – with no guests competing for space along once-crowded pathways – suddenly found time to tackle long-overdue maintenance projects.

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The Conservation & Research staff, with much of their field work on hold, discovered much-needed time for writing critical grant requests for supporting their work. The Programs team, with most schools closed, suddenly found high-tech ways to take the Garden to at-home classrooms by offering virtual tours and other online educational activities for keeping students engaged. And still other employees impacted by the closing found their jobs repurposed, lending a hand where needed, whether weeding flower beds or helping out in the community on an urban farm. Learning to pivot in a pandemic has proven the ultimate test of creativity among those dedicated to the critical mission of connecting people with plants, as their work shared in this third annual issue of PlantIntel attests. Like life itself, the Garden truly blooms on.

DANNY FLANDERS PlantIntel Editor

On the cover: Bryn Pipes of The Nature Conservancy monitors red milkweed with former Garden staffer Lila Uzzell in Georgia.


Milkweed + Monarchs Efforts to conserve imperiled wildflower on which butterflies depend extend throughout Georgia

By EMMA NEIGEL

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Milkweed and Monarch butterflies share a co-evolutionary relationship: The perennial plant species (Asclepias sp.) is named for its milky latex sap that deters predators such as insects from feeding on it – insects except for Monarch caterpillars, that is. The caterpillars have adapted a tolerance to the sap, allowing them to feed on the plant, which in turn deters predators such as birds from eating them. Those caterpillars evolve into butterflies, which later pollinate the milkweed – the only plant on which Monarchs will lay their eggs. These interdependencies link the lifecycle of the two species. The great Monarch migration from North America to Mexico’s Oyamel fir forests every year spans more than 3,000 miles and multiple generations of Monarchs. More milkweed stems mean more food sources and habitat for the Monarchs, which are declining because of threats to the species, such as habitat loss. Fewer than 2 billion stems exist in the United States, but double that amount is needed to help re-establish Monarch overwintering populations. That’s why safeguarding imperiled milkweeds, including several species in Georgia, is so critical for ensuring that species diversity is secured for the future.

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TOP: Former Garden field biologist Lila Uzell and Matthew Stoddard of the Georgia Department of Natural Resources monitor Savanna milkweed. ABOVE: Conservation Horticulturist Emma Neigel checks a GPS location of swamp milkweed (Photo by Alan Cressler)

Native milkweeds are adapted to local conditions, so planting these will help provide the food and habitat needed by the Monarchs. Throughout Georgia, the four critically imperiled milkweeds include purple milkweed (Asclepias purpurascens), red milkweed (A. rubra), swamp milkweed (A. incarnata ssp. incarnata), and Savanna milkweed (A. pedicellata). Threats to the species include habitat loss from woody shrub and tree encroachment in fire-suppressed areas, land conversion and the broad use of herbicides. Among the conservation efforts throughout North America is a project by the Garden involving Georgia’s imperiled species. With support from a field botany research grant from the Georgia Botanical Society, the Garden is partnering with others to conserve them. The goal is to collect seed from wild populations, safeguarding plants at the Gainesville conservation nursery and depositing the remaining seeds in the conservation seed bank to preserve the species’ genetic diversity.


WHY IT MATTERS

Collaboration through nonprofit and governmental partnerships promotes success in preserving rare species. Multiple maternal lines, each associated with a unique identifier and GPS point, were collected so the lineage of each seed can be traced back to the individual plant it was collected from. Seed was collected from populations that occurred in habitats ranging from swamp bogs to coastal islands, and after many long days in the field, more than 50 maternal-line seed collections were established. Germination trials have begun in the Garden’s micropropagation lab, with 100 percent success, and this spring seeds that germinated will be planted at the conservation nursery for safeguarding. The project has been made possible with the support of the Georgia Department of Natural Resources, Georgia Power, Berry College, The Nature Conservancy, Chattahoochee Nature Center, St. Simons Land Trust, Georgia Botanical Society and Alan Cressler.

EMMA NEIGEL is a Conservation Horticulturist at the Garden’s Conservation Safeguarding Nursery.

Georgia’s Imperiled Milkweeds

DID YOU KNOW? • Historically, the fluff from the milkweed seeds, which aids in air dispersal of the seeds (similar to dandelions), was harvested for filling life preservers for soldiers in World War II. • Monarch caterpillars can sequester more than .25 mg of cardenolides from the milkweed sap, which is the same amount given to heart patients in the hospital, even though a Monarch weighs on average less than one gram and a human is 2.5 million times that mass. • Mysteriously, Monarchs know exactly how to migrate every year to Mexico where their greatgreat grandparents had originated from – without a map!

HOW TO HELP Here’s how backyard gardeners can help promote habitat for Monarchs and other pollinators: • Plant native varieties of milkweed. Four that grow in Georgia are Whorled Milkweed (Asclepias verticillata), Clasping Milkweed (A. amplexicaulis), Butterfly Weed (A. tuberosa) and Red-ring Milkweed (A. variegata).

A. purpurascens

A. incarnata ssp. incarnata

• Consider replacing tropical milkweed (A. curassavica) with a native milkweed, or be sure to cut back the tropical species at the end of the season to deter Monarchs from overwintering on this non-native plant. • Avoid use of pesticidal and herbicidal sprays.

A. pedicellata

A. rubra

• Get involved in citizen science through Monarch tagging in your area (Check out Monarch Watch at monarchwatch.org for information).


Cymbidium sinense 6 PlantIntel


Orchids indoors and OUT Through multiple sources, Garden expands terrestrial collection to Storza Woods By SCOTT MCMAHAN and AMANDA BENNETT Most are familiar with the Garden’s flagship display of tropical species orchids, including its nationally accredited Stanhopea and Gongora collections. But it may come as a surprise that for decades the Garden has grown orchids outdoors as well. Bletilla, Calanthe, Cymbidium and both native and nonnative Cypripedium have been nestled around the garden like the valuable jewels they are. Yet not until recent years has the Garden begun to more fully realize the potential for this group of hardy plants. Several native and non-native genera, or groups of species, grow well in the Southeast. Bletilla are probably the best known and least finicky. But Calanthe discolor and Cymbidium goeringii are two Asian species at the Garden that enjoy average pH and soil moisture. Cypripedium kentuckiense and C. acaule are two native species that are cultivated with some pH and moisture adjustments. As the Garden focuses on building its plant collections in Storza Woods, dozens of terrestrial orchids have been planted along the Azalea Walk – a stretch of path with scores of native Rhododendrons. The combination of the two collections will someday create an unparalleled guest experience.

Calanthe x ‘Kozu Spice’

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Cypripedium kentuckiense Last year, the Garden received a gift from Clark Weisner, a Garden member and volunteer, that enabled staff to order both native and non-native orchids. More than 850 orchids representing six genera were obtained from both national and international sources. This generous gift ignited much excitement among staff. Cypripedium pubescens, C. ‘Barry Phillips’, Calanthe sieboldii and Cymbidium ensifolium are just a few of the species that have been added to Storza Woods. In addition, several years ago staff collected seed of several hardy orchid species in northwest China through the Garden’s International Plant Exploration Program, such as Cremastra, Epipactus and Goodyera. At the time, the Garden did not have room in its Ron Determann Micropropagation Lab to begin growing the seed, so they were sent to colleagues at Longwood Gardens and about a year ago the first of those collections began arriving – an exciting delivery because it typically takes three to five years to grow orchids to a plantable size. The young seedlings were planted in a nursery at the Gainesville Garden in hopes that they would acclimate and grow quickly. An additional eight batches of seedlings of different wild-collected species are expected to arrive in the next couple years. Because of the pandemic’s impact on travel, collecting trips have been on hold, but future ones will ensure the Garden’s ability to add Asian orchids. Regarding native orchids, the Garden’s conservation staff legally collect orchid seed for safeguarding and propagation,

WHY IT MATTERS Collaboration yields opportunities for expanding collections, demonstrating a garden’s commitment to plant displays for generations to enjoy. 8 PlantIntel

Cypripediums display strong root development.

as well as growing for internal horticulture displays. Collecting trips throughout the Southeast have netted additional Cypripedium kentuckiense, Platanthera ciliaris, P. psycodes, P. blephariglottis, P. integra, Eulophia alta, Aplectrum hyemale and Spiranthes sp. to display in Storza Woods and elsewhere. Having a source of legally collected native orchids is a tremendous advantage because many on the market are poached from the wild. With multiple departments involved at such an intensive level, guests will soon be able to experience orchids at an intimate level both indoors and out.

SCOTT McMAHAN is the Garden’s Manager of International Plant Exploration AMANDA BENNETT is the Garden’s Vice President, Horticulture & Collections. Tolum-


Cybidium goeringii

Garden horticulturists plant hardy orchids atlantabg.org 9


u o y o t g n i com

n e d r a G from the By LORIN BOREN Jodi Stanford had a problem. A wasp had taken up residence on her back porch, and she wanted it gone. She gave her fourth- and fifth-grade students at Mead Elementary School in Perris, Calif., the task of finding a sustainable and eco-friendly solution to rid her home of the pest. One resourceful student suggested using carnivorous plants, and the search for more knowledge began. Meanwhile at the Atlanta Botanical Garden, the School Programs team was busy launching a new program to connect teachers and students to Garden staff in real time. The coronavirus pandemic had brought all previous in-person field trips and school visits to an abrupt halt in the spring, and though instructors quickly pivoted to continue classroom support through online lessons and videos, it wasn’t as fulfilling as face-to-face interactions. Determined to reach their school audiences with engaging digital content, the staff spent the summer designing virtual tours inspired by other institutions. Through the use of online broadcasting software, the team could combine the structure and informative nature of a newscast with the real-time interaction and fun of a video game streamer to create digital sessions that were both immersive and educational. By midAugust, staff had created six unique virtual tours: “Alice’s Wonderland Reimagined,”

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WHY IT MATTERS

Community engagement is a Garden goal in using plants to provide education and enjoyment. “Carnivorous Plants,” “Frog Talk,” “Desert Discovery,” “Rainforest Ramble” and “Plant Careers.” Each program was designed as a 30-minute session that could be scaled up or down for K-12th grade needs and free for Title I schools. As Garden instructors were sharing virtual tours with their first-session registrants, Stanford’s students in California were making new discoveries. After stumbling upon the Garden’s spring video, “It’s a Trap: Pitcher Plant Pitfalls,” students became even more interested in these insect-eating plants. With further investigation, the teacher found the field trip opportunity on the Garden’s website and signed up for a carnivorous plant virtual tour. She was able to connect her students directly to Garden staff to take a deeper look at how and why plants like Venus flytraps, sundews and pitcher plants prey on animals to survive. And while her students have discovered that

carnivorous plants are not a viable solution for wasp control in California -- pitcher plants prefer much soggier soils -- they did manage to make some fellow scientist friends more than 2,000 miles away. “I will book again and again,” Stanford said. “Please keep the virtual field trips going even after COVID . . . ” Many other schools have followed suit and registered their classrooms for virtual tours. While some of the Garden’s sessions are shared with out-of-state friends from Pennsylvania and Texas, most are held with students in the metro Atlanta area. Interest in the program seems to have gained momentum, allowing the Garden to work with 5,276 students during 205 sessions, making up 93 percent of the Garden’s fall 2019 impact before the pandemic. Overall, feedback has been positive. Linda Stewart of Dekalb Elementary School of the Arts shared her gratitude. “ During this very unprecedented time in our personal and professional lives you have made the virtual learning journey exciting for our students and teachers,” she said. “We really appreciate the time and effort that you have made to continue to provide quality experiences for students across the metro Atlanta area.” LORIN BOREN is the Garden’s School Programs Assistant Manager.


Zana Pouncey, School Programs Coordinator, reads books, dissects flowers and more for students in Atlanta and beyond through a virtual tour session. atlantabg.org 11


WHY IT MATTERS WHY IT MATTERS Monitoring habitats

Seedplants storage of rare is is critical for critical to preserving conserving of the populations genetic diversity threatened plants ofconservation the most through endangered plants. and research. 12 PlantIntel

Isotria medeoloides


Orchid watch Garden monitors federally threatened pogonia species for increasing plant populations By EMILY COFFEY and LILA UZZELL The small whorled pogonia is an inconspicuous terrestrial orchid widely found across eastern forests of the United States and Canada. Yet, despite its broad range, populations are few and intermittent, with three focal centers: New England, Virginia and the southern Appalachian mountains. Given its population scarcity, Isotria medeoloides is federally listed as “threatened” and globally as “imperiled.” Residential development, deer browsing and forest management decisions that alter its habitat are primary threats to this species. Small whorled pogonia populations in the Northeast are relatively stable and well-studied. Mechanical experiments there have shown that select canopy thinning enhances the number of stems and flowering. At the southern extent of their range, however, small whorled pogonia populations in north Georgia are in decline. To assess the situation, the Garden is conducting a five-year study observing dormancy trends and testing techniques for the small-whorled pogonia in north Georgia, the results of which will inform management approaches for increasing the number and richness of wild populations. In the first phase, the Garden monitored populations, tracked dormancy and flowering, and collected nondestructive seed and root samples to explore reproductive viability and the orchid’s symbiotic relationship with associated soil mycorrhizae. The work is being conducted to seek a better understanding of the southeastern populations of this threatened species. Since initiating this effort in 2019, the Garden has rediscovered three populations

recently thought to no longer exist in the region and has counted a total of 247 plants across 10 of those extant sites in north Georgia. Seed and root samples were collected last fall across sites containing reproductively mature individuals. Seed germination trials and fungal baiting conducted in the Garden’s Micropropagation Lab will allow staff to propagate small whorled pogonia seedlings, identifying mycorrhizal species and relationships, and secure plants for safeguarding collections. In the second phase of the research, Garden biologists will partner with the USDA Forest Service to establish a maintenance plan for small whorled pogonia in the southeastern Appalachian Mountains by testing the effects of canopy thinning and prescribed fire. The Garden aims to expand the health and range of small whorled pogonia as well as retain genetic and living material for long-term safeguarding. EMILY COFFEY is the Garden’s Vice President, Conservation & Research; LILA UZZELL is a former Conservation Assistant.

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stunk the year that

2020 unfurls a continental first when a rare corpse flower blooms in the Garden’s Fuqua Conservatory By PAUL BLACKMORE

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Looking back, it’s difficult to find many bright spots in the challenging past year. Yet, one unexpected event did give Garden staff a much-needed distraction from the ongoing drudgery of life during the coronavirus pandemic: For what’s believed to be the first time in North America a rare and mysterious African Corpse Flower bloomed at the Garden. Native to the tropical rainforests of west Africa, where it is threatened by habitat loss, this species, Pararistolochia goldieana, also is believed to be the largest flower in Africa. It was first mentioned by Sir Joseph Hooker in 1865 and noted by J. D. Kennedy in his Forest Flora of Southern Nigeria in which he gives a name translated as “The Grove of the King of the Dead”. The name is believed to be derived from the strong stench of decaying flesh the flower emits in an effort to attract flies as pollinators. As with other species of the plant, the African Corpse Flower forms a large vine emerging from a buried tuber on the forest floor. The vine has shiny dark green, heart- shaped leaves and may grow for several years before it flowers. The saxophone-shaped flowers emerge from the base of the vine just above the soil and are believed to be the largest in the Aristolochiaceae family; the bloom can reach the size of a large bucket when mature. Once open, the red, purple and yellow flower lasts for about three to five days and if pollinated will produce a seed pod.

WHY IT MATTERS

Displaying rare plants supports the Garden’s mission in educating guests about the importance of the conservation of threatened species.

Ecologically, this species is very important, believed to be a food plant for the African giant swallowtail (Papilio antimachus), the largest and most toxic butterfly in Africa.

Since its discovery, the African Corpse Flower has attracted plant collectors from around the world. The plant’s mysterious nature has made it the holy grail of collectors and growers who go to great lengths to obtain a specimen. In 2017, seedlings were donated to several public gardens in the United States, including the Atlanta Botanical Garden, by researcher Alex Eilts, an ecologist at the University of Minnesota’s College of Biological Sciences. At the Garden, the vines soon outgrew their home in the greenhouse and were transplanted to the Fuqua Conservatory where they quickly rambled off into the canopy. Last June -- much to the staff’s surprise -- one of the plants produced a large (about 12 inches long by 6 inches wide) and very odorous flower. Eilts confirmed that research showed the Garden may be the first in the Americas to get this African treasure to flower (By all accounts, the last recorded flowering outside Africa was in the Berlin Botanical Garden in the 1920s). A bright – yet smelly – spot in 2020 indeed.

PAUL BLACKMORE is the Garden’s Fuqua Conservatory & Conservation Garden Manager.

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A volunteer for Truly Living Well lays mulch between beds to prevent weeds.


Feeding a cause Garden lends a hand to city’s largest urban farm in supplying fresh food – and growing know-how By MOE HEMMINGS


Steps from the educational pillars attended by Martin Luther King, Jr., Spike Lee and Stacey Abrams lies a 3.5-acre urban farm that seeks to change the way people think about food.

The Truly Living Well Center for Natural Urban Agriculture – located in a historic Atlanta neighborhood the U.S. Department of Agriculture has deemed a “food desert” – aims to not only be a source of fresh vegetables but also to teach residents how to grow their own. To help with that mission, the nonprofit farm has enlisted the support and expertise of organizations such as Atlanta Botanical Garden. Founded in 2006, the farm moved four years ago from its original site in the Old Fourth Ward neighborhood to Ashview Heights, one of the first planned developments built in the 1920s for Atlanta’s middle-class African American community. Situated on a former public housing development, the farm leased the land from the Atlanta Housing Authority until last year when it was deeded the property with the stipulation that it continue serving as an agricultural and a community resource. “Historically, African-Americans have lost so much land in this country since the 1900s,” said Carol Hunter, the farm’s Executive Director. “Anytime we are able to reclaim land for farming, it’s good for the community.” For the past three years, the Garden has collaborated with Truly Living Well to build a relationship developed with education, trust and mutual support. What started as a conversation between two leaders now includes educational program development, mentoring emerging leaders and even hands-on farm support and gardening.

Garden volunteer Heather Tangren takes cuttings from a garden bed.

Volunteers pitch in to help the urban farm staff tend the Garden.

At the beginning of the collaboration, Hunter, knowing the Garden’s emphasis on educational programs and community outreach, sought to strengthen the farm’s relationship with M. Agnes Jones Elementary located across the street. Until that point, students would visit for activities such as starting seeds, turning compost and a class favorite, harvesting. To support the school’s goal of becoming


STEAM (Science. Technology. Engineering. Art. Math) certified in the state, Garden staff worked with Truly Living Well to develop on-farm backpack experiences. Four backpacks were developed with topics such as pollinators, farm exploration, the senses and composting. Each is designed to be utilized by up to 25 students or a family of four so that students who do not participate with their class can still enjoy the fun of learning. Because of Ashview Heights’ “food desert” designation, an integral part of the farm’s mission is increasing residents’ access to fresh produce as well as encouraging them to grow their own food, even on a small scale. But last year’s outbreak of the pandemic brought its share of challenges, especially coinciding with the spring and summer growing season when the farm relies heavily on volunteers. Garden staff helped ensure that crops got planted and harvested by providing their time and expertise three days a week. That hands-on support proved critical in helping Truly Living Well rise to the demand for fresh local food. In addition, the Garden has supported the farm’s annual Martin Luther King Jr. Day of Service, for the past two years helping with several beautification projects such as mulching, weeding and building cold frames and seeding tables.

WHY IT MATTERS

Growing fresh food encourages consumers to eat healthy while also cultivating sustainable gardens and productive communities.

“The Garden’s partnership with Truly Living Well has grown significantly in the last few years,” said Mary Pat Matheson, the Garden’s President & CEO. “The farm is a green anchor in the Westside community, providing fresh produce, learning opportunities and a green respite to people who live there. So we are committed to helping Carol and her team grow their gardens and programs for the benefit of that community.”

Raised vegetable beds dominate the urban farm, the city’s largest.

MOE HEMMINGS is the Garden’s Community Outreach Manager.

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Living fossil

Everything about the plant Welwitschia is, well, strange By TREY FLETCHER The Fuqua Conservatory’s Desert House holds many plants that could be described as strange, unusual – even bizarre – but perhaps none deserves such a label as much as Tumboa, Welwitschia mirabilis. Found growing only in a narrow range in the extremely arid coastal regions of Namibia and Angola, Welwitschia is distinguished by its twisting, frayed, pale green leaves, and from a distance might not appear to be living at all. Uniquely, each plant has only two long ridged leaves, growing very slowly from the center of the plant. The leaves twist along the ground around the base of the plant and often split multiple times. They can grow to lengths approaching 13 feet, and the constant abrasion by sand in the hot desert winds gives them a ragged appearance. Smaller plants may look like two strips of wide green tape sprawling along the ground, but some larger specimens can grow to be as tall as a person, with the leaves spreading as much as 8 feet from the center. Welwitschia is not simply strange in appearance. While it is a gymnosperm, or cone-producing plant like cycads, conifers and Ginkgo trees, it has been classified as the only member of its family and has no close living relatives. For this reason, it is sometimes called a “living fossil”. A number of adaptations have allowed Welwitschia to survive in the harsh Namib Desert, where many years may pass without precipitation in the form of rain, and fog rolling in from the Atlantic Ocean can be the only source of moisture. The plants are frequently found growing along dry river beds that can allow the long taproot to take advantage of water deep beneath the surface. Their leaves may sometimes change color depending upon the availability of moisture as well, turning reddish when conditions are drier in order to reflect solar radiation and green again in wetter times for facilitating photosynthesis and growth. Because of its toughness along with a very slow rate of growth, Welwitschia can survive for centuries, and some individual plants have been estimated at more than 1,000 years old. Over their lifespans, some larger individuals can anchor enough sand around their bases to form dunes. Even with the many fascinating examples of desert plant biodiversity on display in Desert House, Welwitschia stands out among the strangest of the strange. 20 PlantIntel

Welwitschia, such as this one growing in Desert House, can survive for centuries.

WHY IT MATTERS Displaying plant collections for education and enjoyment plays a major role in the Garden’s mission. TREY FLETCHER is Curator of the Garden’s Desert House.


INDOOR

BEAUTIES Lesser known tropical rhododendrons thrive as epiphytes By MIKE WENZEL atlantabg.org 21

Rhododendron himantodes


Those big showy rhododendrons brightening yards around Atlanta are a familiar site every spring. But what most may not know is that there is a tropical group of the species that can be grown indoors – some of which can be enjoyed at the Garden year round. Often referred to as tropical, or vireya, rhododendron, this subgenus represents about one-third of all Rhododendron species. Yet, this group is often the least familiar because of its native climate of tropical mountains from south China to New Guinea. At the Garden, the Fuqua Orchid Center’s Tropical High Elevation House is home to about a dozen representatives of this fascinating and beautiful plant group. There, these species are provided with the cool and humid atmosphere they often require to thrive and bloom throughout the year. Frequently, these species grow as epiphytes in the wild, which impacts their cultivation. That means the roots need to be provided with a well draining and airy yet moist environment, similar to how many orchids are grown. Many of the species are very slow growing and sensitive to high concentrations of fertilizer.

Slowly growing to 3 feet, R. taxifolium is an epiphyte native to Mt. Pulog and at even higher elevations in the Philippines. Delicate groups of one-inch white, bell-shaped flowers are a surprising contrast to the exceptionally narrow foliage that at casual glance might be mistaken for a conifer when not in flower.

Some of the plant’s variety of growth forms and flowers can be seen in a few examples thriving at the Garden (right): MIKE WENZEL is the Garden’s former Manager of Plant Documentation.

Rhododendron laetum ‘Golden Gate’ 22 PlantIntel

A terrestial species that tolerates more warmth growing in the center’s Orchid Display House is R. rarilepidotum, which eventually can grow to more than 10 feet high. Native to Sumatra at somewhat lower elevations, it produces stunning globes of up to 12 glossy red flowers.


Rhododendron praetervisum typically grows as an epiphyte to 6 feet high and is native to Sabah, including Mt. Kinabalu, at high elevations. This species produces striking pendulous clusters of purple flowers.

WHY IT MATTERS WHY IT MATTERS Enticing plant

Seed storage collections are key is critical for in connecting people conserving with nature.the genetic diversity atlantabg.org 23


The Garden’s Jason Ligon, left, and forester Kristen Brannon carefully excavate root tip samples of Chapman’s Fringed Orchid at a Florida state park. 24 PlantIntel


Digging deeper In search of answers to how species of native terrestrial orchids evolve By JASON LIGON atlantabg.org 25


Hiking proved a popular pastime last summer for folks craving a break during the pandemic. Those who were outdoors likely passed by Platanthera, the genus of plants containing the most species of terrestrial orchids native to North America. Naturally occurring hybrids make distinguishing between orchid species difficult. Further, two closely related species, one having yellow flowers with a short nectar-filled spur and the other with more orange-yellow flowers with a much longer spur, coexist, side-by-side, without breeding. Or do they? While subtle, these distinctions are critical when the former is a protected species while the latter is considered common or globally secure. How should their hybrids be classified, and how do species come to be? To address those questions, the Smithsonian Environmental Research Center, with funding from the American Orchid Society, is working with the Garden to investigate two possible drivers of the formation of new and distinct species within the Platanthera genus: hybridization and fungal specificity across Platanthera’s orange and purple complexes. The Garden’s contributions to the project include collecting flower measurements and leaf and root samples from Georgia, Tennessee, Florida, North Carolina and Texas, which are being analyzed with others collected by the center in the Mid-Atlantic and Northeast. Whether in Florida’s grueling heat or Tennessee’s summer downpours, meticulous flower measurements were taken to illuminate morphological differences in flowers of different species

P. chapmanii and their hybrids. Leaf samples were sequenced on a molecular level to determine the relationships among individuals. Root samples represent the deepest dive into the question of Platanthera speciation, the process by which populations evolve to become distinct species. You may think you know a plant -- until you’re on your hands and knees, searching for one root of the brownish-yellow color signifying a likely host for the desired mycorrhizal fungi. Careful field protocols ensure that the delicate orchid plant is not threatened during the root sampling. Sometimes digging for roots submerged in a mountain stream or coming up short with barely any lateral roots to sample, Garden staff still managed to carefully collect a root from up to six plants per species at each site. Back in the lab, root samples were kept cool and divided between the center and the Garden to be analyzed. It took about 50 hours of painstaking work under the microscope using a scalpel to shave each root and identify and collect the bundles of fungal hyphae, making it all the more satisfying when they were cultivated successfully in the lab. By the time the project is completed, all involved will have a better understanding of Platanthera speciation – and a greater appreciation for the collaboration it took to get there.

P. blephariglottis

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JASON LIGON is the Garden’s Micropropagation & Seed Bank Laboratory Coordinator.


WHY IT MATTERS

Understanding the diversity of plant populations is critical in best efforts to conserve them.

John Evans, the Garden’s Conservation Horticulture Coordinator, uses calipers to take precise floral measurements. atlantabg.org 27


M. ashei

MAGNIFICENT

MAGNOLIAS Garden leads global effort to rescue plant species threatened by loss

By JEAN LINSKY 28 PlantIntel


Magnolias are a Southern icon, their strikingly bold flowers and sweet floral scents making them a popular choice in gardens and as street trees. But what’s not well known is the fact that nearly half of the species around the world is highly threatened with extinction.

WHY IT MATTERS

To prevent further loss, the Garden is leading an international effort to save Magnolias. Logging, habitat clearance and climate change across their wild ranges in the tropics of America and Asia are the tree’s leading enemies. Recent analysis of all Magnolia species shows that 51 percent of the 335 known species are threatened with extinction. That means they are considered “critically endangered,” “endangered” or “vulnerable” on the International Union for Conservation of Nature Red List of Threatened Species, the world’s most comprehensive inventory of the global conservation status of biological species.

M. faustinomirandae

Collaboration through volunteer and governmental partnerships can yield success in preserving endangered plant species.

The great need for conservation of Magnolias is evident, and collaboration among partners in the United States and abroad is needed to carry out meaningful actions. Last year, the Garden accepted a leadership role in the Global Conservation Consortium for Magnolia, an initiative developed in collaboration with Botanic Gardens Conservation International to ensure that no wild species of Magnolia becomes extinct. By bringing together global experts, conservationists in botanic gardens, land managers and others focused on Magnolia conservation, the consortium intends to develop integrated strategies. To begin, it is establishing the IUCN Red List status of previously unassessed Magnolia species while analyzing how well represented Magnolia species are in conservation collections. The results will define priority activities for Magnolia species of greatest conservation concern. Specifically, members of the Garden’s Conservation & Research team are working with partners in Mexico to conserve two critically endangered species, Magnolia faustinomirandae and M. montebelloensis. These species are threatened by deforestation and habitat fragmentation in Chiapas, Mexico and neighboring Guatemala. The work will focus on ensuring these species are conserved in botanic gardens in Mexico, analyzing the genetic diversity of these species and implementing management plans for their conservation in the wild.

JEAN LINSKY is a Conservation Biologist at the Garden.

Magnolia seedlings are grown in a nursery in rural Guatemala for reintroduction into the wild. atlantabg.org 29


The Garden’s nationally recognized collections include (left to right): Acer, Gongora, Sarracenia, Stanhopea and Magnolia.

Fresh start

New guidelines underscore the Garden’s commitment to plant collections By AMANDA BENNETT A plant collections policy may sound like just another bureaucratic document, but without one, public gardens are like a ship without a rudder. Collection efforts require such a set of guiding principles for supporting the institution’s mission – and not just one individual’s whims. Because the Garden’s policy had not been updated since 2007, the staff decided to undertake a complete rewrite last year. With 2015’s addition of the Gainesville garden, considerably more robust Conservatory collections, an increased number of outdoor display areas and a complete overhaul of the conservation department, the update was long overdue. A group of 14 staff from four different departments and one Garden trustee spent most of the year on the project, and the result is a dynamic document that well represents the Garden’s collections and future. The revised policy covers the intent, scope of horticulture and conservation collections, support facilities, International Plant Exploration Program, acquisitions and plant 30 PlantIntel

WHY IT MATTERS

Guidelines for plant collections are critical for supporting the Garden’s mission. documentation, with specific guidelines for all hardy and tropical collections identified. The Garden is known for its five nationally accredited Plant Collections Network collections: magnolias, maples, pitcher plants, and Stanhopea and Gongora orchids. Yet, dozens of other taxa, or plant groups, are included in the policy that support the Garden’s mission of “developing and maintaining plant collections for display, education, research, conservation and enjoyment.” In general, the Garden selects plant collections not widely duplicated by other botanical gardens, ones for which its facilities and/or climate are well suited and ones for which the Garden has demonstrated a commitment to

support. Horticultural collections include two types: Collections on Display and Taxonomic Collections. Collections on Display encompasses a themed display area including multiple taxa, such as the Skyline Garden’s Cacti and Succulent Terraces, Conifer Garden, Rose Garden, Tropical Rotunda, Orangerie, Desert House, Tropical High Elevation House and Orchid Display House. Taxonomic Collections include hardy and tropical palms, rhododendrons, conifers, carnivorous plants, begonias and orchids as well as camellias, hydrangeas and others. The rewrite of the plant collections policy underscores an exciting time for the Garden, thanks to interdepartmental efforts, a fresh focus and enthusiasm among staff, as well as the tremendous established collections. The future of the Garden’s plant collections never looked brighter.

AMANDA BENNETT is the Garden’s Vice President, Horticulture & Collections.


PLANT CLOSEUP Lipstick Palm

ORIGINS: Cyrtostachys renda is a member of the Arecaceae family and is native to peat-based tropical lowland swamp forests of the Thailand peninsula to western Malaysia. CLASSIFICATION: Commonly known as Lipstick Palm or Red Sealing Wax Palm, this stunning plant is best known for its distinct, bright red to scarlet crownshaft (leaf sheath). Although never used for sealing wax, the plant’s natural color is indicative of classic vermilion wax seals. An extremely popular and sought-after palm, it’s widely cultivated in the ornamental plant trade. Since the early 2000s, new cultivars have been introduced such as ‘Theodora Buhler’ and ‘Orange Crownshaft’. NOTEWORTHY: There is arguably no palm more eye catching than C. renda when it comes to color. A common staple of gardens and hotels across Southeast Asia, it achieves a bright, clean and contemporary aesthetic wherever planted. For many years a potted specimen has been growing in the Garden’s Fuqua Conservatory Special Exhibits area and now finds a new home as the centerpiece of a newly renovated bed. SIZE: 20 feet by 4 feet clumps with trunks of varying height when fully mature. USES: Primarily as an ornamental, often used in tropical landscapes for stunning border plantings CARE: The key to growing this palm successfully is lots of water. Relatively easy to grow outside in tropical environments with heavy rainfall, but in a greenhouse or conservatory it requires constant watering and high temperatures. PROPAGATION: Seed and layers of offshoot buds PROBLEMS: Rarely susceptible to spider mites and scale

MICK ERICKSON is a Conservatory Horticulturist at the Garden.

Cyrtostachys renda atlantabg.org 31

FAMILY: Arecaceae | ZONE: 11-12 | BLOOM TIME: Continuous once mature| LIGHT: Full sun to part shade | NATIVE: Thailand to Western Malaysia


The mission of the Atlanta Botanical Garden is to develop and maintain plant collections for display, education, research, conservation and enjoyment.

Kalmia latifolia

32 PlantIntel

PlantIntel

| Vol. 3, Issue 1, 2021-22 | The Anna and Hays Mershon President & CEO: Mary Pat Matheson Vice President, Marketing: Jessica Boatright | Editor: Danny Flanders | Designer: Bo Shell


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