Palmetto
Pine Rockland Corridors ● New Hope for Florida Ziziphus ● Cinnecord – Native or Not?
Chapter Liaisons Needed for FNPS Land Management Partners Subcommittee
The Land Management Partners (LMP) subcommittee provides government agencies, non-government organizations, and the general public with support in managing public and private lands to promote the preservation, conservation and restoration of Florida’s native plants and native plant communities.
An LMP liaison from each FNPS chapter is needed to communicate with members about upcoming activities in the area, to identify those interested in participating in LMP activities, and to distribute LMP information to the chapter membership.
Volunteers are also needed to help with local LMP support, including participating in Florida Department of Environmental Protection land management reviews of public lands, assisting with plant surveys, and helping with
monitoring and reporting the results of land management activities on public lands.
The LMP subcommittee will meet at the upcoming FNPS Annual Conference for a brainstorming and education session. In the meantime, for more information on serving as a chapter liaison or volunteer, contact Anne Cox at ecologinc@bellsouth.net or Daphne Lambright at dlambrig@biotechnical-services.com.
Conservation and Research Grants:
FNPS provides up to three conservation grants and three research grants annually with up to $2,500 in funds available for each grant. Visit www.fnps.org for requirements and to download a grant application. Applications due March 6, 2009.
Landscape Awards: Submit your Florida native plant landscaping project to the FNPS Landscape Awards program. Contact Jake Ingram at jakeingramla@comcast.net, or visit www.fnps.org for details and to download an application. Applications due March 6, 2009.
Keynote Speakers: Doug Tallamy and Dan Austin Plenary Speaker: Hal Wanless, Sea Level Rise in Florida
The Status of Conservation in Florida Panel Discussion with:
Greg Brock, Ph.D. – Florida Department of Environmental Protection
Richard Hisenbeck, Ph.D. – The Nature Conservancy
Tom Hoctor, Ph.D. – University of Florida
Reed Noss, Ph.D. – University of Central Florida
Jon Oetting – Florida Natural Areas Inventory Moderator – Gene Kelly, President, Florida Native Plant Society
Field Trips
West Palm Beach Marriott
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Reservations: (800) 376-2292 For Conference discount, ask for FNPS rate
The purpose of the Florida Native Plant Society is to preserve, conserve, and restore the native plants and native plant communities of Florida.
Official definition of native plant: For most purposes, the phrase Florida native plant refers to those species occurring within the state boundaries prior to European contact, according to the best available scientific and historical documentation. More specifically, it includes those species understood as indigenous, occurring in natural associations in habitats that existed prior to significant human impacts and alterations of the landscape.
Organization: Members are organized into regional chapters throughout Florida. Each chapter elects a Chapter Representative who serves as a voting member of the Board of Directors and is responsible for advocating the chapter’s needs and objectives. See www.fnps.org
Board of Directors
Executive Officers
President ....................................Eugene Kelly Past President ............................Shirley Denton Vice President, Administration .....Ann Redmond Vice President, Finance Steve Woodmansee
Treasurer ....................................Susan Thompson
Secretary Christina Uranowski
Committee Chairs
Communications .........................Cindy Liberton
Conference Stephanie Brown
Conservation ..............................Eugene Kelly Suzanne Kennedy
Development Sub-Committee Ray Wunderlich III Education ...................................Kari Ruder Policy & Legislation .....................Annie Schmidt ..................................................Kim Zarillo Landscape Awards ......................Jake Ingram Scott Sager
Media Relations Sub-Committee .....Terry Godts
Membership ...............................Lynka Woodbury
Membership Vice Chair ............... Volunteer Needed Public Lands Management Sub-Committe ............................ Anne Cox Daphne Lambright
Publications ................................Bob Egolf
Science ......................................Paul Schmalzer
Directors-at-Large, 2007–2009 Sue Dingwell
Ray Jarrett
Directors-at-Large, 2008–2010 Lynne Flannery
Rick Joyce
Fritz Wettstein
To contact board members: Visit www.fnps.org or write care of: FNPS – PO Box 278 Melbourne FL 32902-0278
To join or for inquiries: Contact your local Chapter Representative, or call, write, or e-mail FNPS, or visit www.fnps.org. Florida Native Plant Society PO Box 278 Melbourne FL 32902-0278 Phone: (321) 271-6702 info@fnps.org • www.fnps.org
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Palmetto..........................Marjorie Shropshire Editor, Sabal Minor .....................Rosalind Rowe
Palmetto
Features
4 Creating Corridors to Protect Pine Rockland Plants
Learn how Fairchild Tropical Botanic Garden’s Connect to Protect program seeks to develop corridors to alleviate the fragmentation of rare pine rockland habitat in South Florida.
8 Recent Developments Boost Recovery Prospects of Florida Ziziphus
The discovery of five new populations of Florida ziziphus is the most important development for the recovery of this critically endangered plant since its initial rediscovery more than 20 years ago.
12 Native or Not: Studies of Problematic Species No. 4
Acacia choriophylla has been reported in Florida ever since its discovery on Key Largo in 1967. Some have assumed it to be native, others believe it to be an introduction. In his 4th article in a series about problematic species, Dr. Dan Ward investigates the facts surrounding its distribution.
14 FNPS Annual Report
Palmetto seeks articles on native plant species and related conservation topics, as well as high-quality botanical illustrations and photographs. Contact the editor for guidelines, deadlines and other information at pucpuggy@bellsouth.net, or visit www.fnps.org and follow the links to Publications/Palmetto.
ON THE COVER:
Left: Amorpha herbacea var. crenulata. Top right: Native hymenopteran visiting Amorpha herbacea var. crenulata flower Photos by Jennifer Possley. Lower right: Ipomoea microdactyla.
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The Palmetto (ISSN 0276-4164) Copyright 2009, Florida Native Plant Society, all rights reserved. No part of the contents of this magazine may be reproduced by any means without written consent of the editor. The Palmetto is published four times a year by the Florida Native Plant Society (FNPS) as a benefit to members. The observations and opinions expressed in attributed columns and articles are those of the respective authors and should not be interpreted as representing the official views of the Florida Native Plant Society or the editor, except where otherwise stated.
Editorial Content: We have a continuing interest in articles on specific native plant species and related conservation topics, as well as high-quality botanical illustrations and photographs. Contact the editor for submittal guidelines, deadlines and other information.
Editor: Marjorie Shropshire, Visual Key Creative, Inc. pucpuggy@bellsouth.net ● (772) 232-1384 855 N.E. Stokes Terrace, Jensen Beach FL 34957
Connect to Protect:
Creating corridors to protect South Florida’s pine rockland plants
Florida’s burgeoning development has impacted our native flora in a variety of ways, including the loss of critical habitat that supports a number of endangered plant species (Figure 1). The Connect to Protect program seeks to develop corridors to alleviate problems of urban fragmentation on rare pine rockland plant populations in South Florida. Funded by a grant from U.S. Fish and Wildlife Service, Fairchild Tropical Botanic Garden created this program to help conserve the federally listed and candidate species found in this remarkable habitat by doing the following:
1) Developing a participatory network of interested public land manager stakeholders and creating a conservation action plan to include corridors between pine rockland natural areas.
2) Assisting land managers to restore habitats in corridors and implementing site-specific activities that can enhance populations of listed and candidate species.
3) Experimentally determining habitat-specific population growth, seedling germination patterns, and establishment requirements of target species in at least two sites.
4) Providing the lay and scientific public information about habitats, their unique flora, and this research.
The program builds on the idea of utilizing wildlife corridors to promote the survival of plants in these shrinking habitats. This idea has gained international prominence in recent years in efforts
to assist the survival of charismatic megafauna such as elephants. It has also been part of the effort within the state to preserve the Florida panther (Anderson & Jenkins, 2006). The use of corridors can also be applied to the preservation of plants [SIDEBAR 1, page 6].
Background on the pine rockland habitat
South Florida’s pine rockland habitat is one of the most endangered habitats in the world (FNAI, 1990). Pine rockland is typically identified by an open canopy of slash pine (Pinus elliottii var. densa), a lower layer of both tropical and temperate shrubs and palms and a ground cover of grasses and herbs (FNAI, 1990) (Figure 2).
Because it is situated in the subtropics, this region has a rich diversity of temperate and tropical plants represented for a total of 439 species, including a number that are found nowhere else. In fact, the pine rockland habitat is home to 31 endemics, including 6 federally listed species and 9 that are candidates for listing (Figure 1) [SIDEBAR 2, page 6].
The pine rocklands are situated on a limestone ridge some 80 km long and 6 to 14 km wide known as the Miami Rock Ridge (Snyder et al., 1990). Unlike most pine habitats that are prevalent throughout Florida, pine rocklands have limestone substrate known locally as “pinnacle rock” that is often directly on or very close to the surface (Figure 3). Starting in the northeast part of Miami-Dade
Above: Figure 1 –
Top left – Amorpha herbacea var. crenulata, photo by Jennifer Possley. Bottom left – Ipomoea microdactyla.
Top right – Polygala smallii, photo by Joyce Maschinski.
Scott Lewis & Joyce Maschinski, Fairchild Tropical Botanic Garden
County at an elevation of 7 meters above sea level, this limestone layer gradually decreases in elevation to 2 meters as we travel from the north to the south and west. The ridge emerged from the shallow sea 14,000 years ago exposing cemented limestone. Over time, rain and standing water dissolved softer parts of the rock, leading to a pockmarked, sponge-like appearance with scattered, deep sinkholes. Soils are composed of sand, marl, and organic materials that accumulate in rock depressions.
Because it is located at the tip of continental United States, pine rocklands have a climate that is considered subtropical. Its temperatures are fairly uniform across the year, with a summer average of 27° C (81°F) in July and a winter average of 18° C (64°F) in January. There are occasional freezing events in winter, which limits the establishment of cold sensitive species (Snyder et al., 1990). Precipitation occurs mostly in the form of seasonal rain, averaging 64 inches (163 cm) that falls primarily during the summer months from June to September.
Historically, the relatively elevated pine rockland areas provided early settlers with a place where they could situate their homes without fear of flooding. Pine trees found in this area also provided opportunities to create a timber industry and rail lines were built through the heart of the pine rocklands to assist in tree harvesting. In more recent years, South Florida’s mushrooming development has shrunk the size of pine rockland habitat to less than 2% of what it once encompassed in the 1800s (Figure 4).
The remaining pine rockland fragments in Miami-Dade County are under increasing pressure from a number of sources, including continued development and invasive species. According to the Florida Exotic Pest Plant Council’s 2007 List of Invasive Plant Species (http://www.fleppc.org/list/07list_ctrfld.pdf), 62 Category 1 invasive exotics exist in South Florida, making the pine rockland habitat especially vulnerable to this type of stress. When visiting unmanaged private holdings of pine rockland property as part of our work on the Connect to Protect project, it is not unusual for us to find large numbers of invasives, such as Schinus terebinthifolius (Brazilian pepper), Neyraudia reynaudiana (Burma reed), Casuarina equisetifolia (Australian pine), Acacia auriculiformis (ear-leaf acacia), and Albizia lebbeck (Woman’s tongue).
Fire, long the critical source of renewal and nutrient recycling for these habitats and a natural way to suppress the growth of invasives, has been severely restricted due to safety concerns within the
Above: Figure 4 – Original and remnant pine rocklands. Map developed by Karen Minkowski, Keith Bradley and George Gann.
Above: Figure 2 – Pine rockland site. Photo by Sam Wright. Below: Figure 3 – Limestone in pine rockland exposed after fire.
An important strategy for biological conservation is establishing wildlife corridors between natural areas that may permit organisms to survive while small, fragmented patches may not (Defenders of Wildlife, 1991).
For example, connecting two areas with a planted avenue may permit pollinators and seed dispersers, such as birds, to travel between the two. As they travel, pollinators and dispersers will increase movement of pollen and seeds, making it more likely that gene diversity will increase. Gene diversity may increase the likelihood that populations of endangered plants and animals will be maintained in the face of catastrophic events like flooding or intense hurricanes because there is a greater range of individual responses and adaptations in more genetically diverse groups.
Recent research shows that plants found in areas that were connected by patches showed better survivorship and gene diversity than those that were not connected (Damschen et al., 2006). In areas such as Miami-Dade County where largescale fragmentation has occurred, promoting such connections may be our best bet for promoting plant survivorship.
In addition, providing corridors with native plants may allow the public to become more familiar with these unusual species. Corridors established with pine rockland species along bike or footpaths will help the general public see these beautiful plants close up and integrated into their urban setting.
2 – Plants in the Pine Rockland
Currently, 439 native plant species are found in the pine rockland habitat, including the following:
Federally listed as endangered or threatened
Amorpha herbacea var. crenulata ............... E
Chamaesyce deltoidea subsp. adhaerens E
Chamaesyce deltoidea ............................... E
Galactia smallii ........................................... E
Polygala smallii .......................................... E
Chamaesyce garberi .................................. T
Candidates for federal listing
Argythamnia blodgettii ............................... C
Brickellia mosieri ........................................ C
Chamaecrista lineata var. keyensis ............ C
Chamaesyce deltoidea subsp. pinetorum ...... C
Chamaesyce deltoidea subsp. serpyllum C
Dalea carthagenensis var. floridana............ C
Digitaria pauciflora ..................................... C
Linum arenicola.......................................... C
Linum carteri .............................................. C
KEY:
C = Candidate E = Endangered T = Threatened
Listed by the state of Florida as endangered or threatened
highly populated urban and suburban areas in Miami-Dade County. However, if fire does not occur regularly in a pine rockland (about every 3-7 years), there is a good chance that succession from pine rockland hammock species will take place. Without fire, forest litter and dead branches accumulate suppressing the growth of many kinds of plants; when fire does occur, the intensity will be so great that it will damage natives that normally thrive after less intense burning (FNAI, 1990). Recent research focusing on management alternatives to burning shows that mechanical thinning of the accumulated duff that limits seedling growth does result in greater species diversity without increasing exotic invasives (Maschinski et al., 2005). Unfortunately, such work is labor intensive and expensive.
Pursuing the program goals
The Connect to Protect Network is pursuing several initiatives to satisfy its objectives.
A number of the remnant pine rockland areas are located within protected natural areas that are managed through the County’s Natural Areas Management (NAM) division. These include properties that were recently acquired through the Environmentally Endangered Land (EEL) program – a Miami-Dade County voter approved effort to acquire, protect, and maintain environmentally endangered lands. These areas can be thought of as islands in the sea of the MiamiDade County urban and suburban landscape. We are working with Miami-Dade County to increase the numbers of pine rockland plants incorporated into the December 2007 Miami-Dade County Parks and Open Space System Master Plan. The County Plan seeks to promote a more sustainable living area by promoting greenway connections among parks, public spaces, natural and cultural areas. The County greenways overlap some 60-70% of our proposed corridors. Thus, we are encouraging the County to incorporate pine rockland plants in these corridors as much as possible. In this way, we hope to build connections or stepping stones between pine rockland natural areas (Figure 5).
Aletris bracteata .........................................
Alvaradoa amorphoides ..............................
Basiphyllaea corallicola ..............................
Bourreria cassinifolia ..................................
Caesalpinia pauciflora ................................ E
Catesbaea parviflora ..................................
Catopsis berteroniana ................................ E
Chamaesyce porteriana.............................. E
Colubrina arborescens ............................... E
Colubrina cubensis var. floridana ................
Cyperus floridanus .....................................
Cyrtopodium punctatum .............................
Dodonaea elaeagnoides .............................
Ernodea cokeri ...........................................
Evolvulus grisebachii ..................................
Glandularia maritima ..................................
Hypelate trifoliata .......................................
Ipomoea microdactyla ................................
Ipomoea tenuissima ................................... E
Jacquemontia pentanthos ..........................
Koanophyllon villosum ................................ E
Lantana canescens .................................... E
Lantana depressa ....................................... E
Lechea divaricata ....................................... E
Linum carteri var. smallii ............................ E
Ocimum campechianum ............................ E
Odontosoria clavata .................................... E
Oncidium ensatum ..................................... E
Pisonia rotundata ....................................... E
Poinsettia pinetorum .................................. E
Ponthieva brittoniae.................................... E
Psychotria ligustrifolia ................................ E
Scutellaria havanensis ............................... E
Selaginella armata var. eatonii.................... E
Spiranthes torta .......................................... E
Strumpfia maritima .................................... E
Stylosanthes calcicola ................................ E
Tephrosia angustissima var. corallicola E
Thrinax morrisii .......................................... E
Thrinax radiata ........................................... E
Tillandsia fasciculata var. densispica .......... E
Tillandsia utriculata .................................... E
Trema lamarckianum ................................. E
Angadenia berteroi ..................................... T
Bletia purpurea........................................... T
Byrsonima lucida........................................ T
Chamaesyce pergamena ............................ T
Chaptalia albicans ...................................... T
Chrysophyllum oliviforme ........................... T
Coccothrinax argentata .............................. T
Crossopetalum ilicifolium ........................... T
Crossopetalum rhacoma ............................ T
Cynanchum blodgettii................................. T
Digitaria filiformis var. dolichophylla ...........
Ilex krugiana...............................................
Jacquemontia curtisii .................................
Jacquinia keyensis .....................................
Manilkara jaimiqui subsp. emarginata ........ T
Melanthera parvifolia..................................
Pithecellobium keyense..............................
Psidium longipes ........................................
Pteris bahamensis ......................................
Pteroglossaspis ecristata............................
Reynosia septentrionalis.............................
Rhynchosia parvifolia .................................
Sachsia polycephala...................................
Senna mexicana var. chapmanii .................
Smilax havanensis .....................................
Solanum donianum ....................................
Spermacoce terminalis...............................
Swietenia mahagoni ...................................
Tetrazygia bicolor .......................................
Tillandsia balbisiana ...................................
Tillandsia flexuosa ......................................
Tillandsia variabilis .....................................
Tragia saxicola ...........................................
SIDEBAR
Using satellite imagery and knowledge of the area, we have located remnant pine rocklands on private properties and asked landowners to take steps to maintain them. We have discussed the project with landowners, provided support for identifying and clearing invasives, and given away pine rockland plants to help restoration efforts.
We have asked schools located near corridors and natural areas to serve as “stepping stones” between natural areas by planting pine rockland gardens so that pollinators might utilize school ground plantings to refuel as they travel back and forth between the remnant areas. In conjunction with the Fairchild Challenge Program, teachers and students have helped us plant pine rockland gardens, cleaned up pine rockland parks, designed logos for the project, and conducted germination research projects utilizing seeds from pine rockland plants (Figure 6). (http://www.fairchildgarden.org/index.cfm?section= education&page=fairchildchallenge)
To build our knowledge of the cultivation and storage capabilities of pine rockland plants, we are researching their germination requirements and testing whether seeds can withstand desiccation and freezing (Figure 7). Many pine rockland plant species have dormancy that requires cold stratification or acid treatments before they will germinate. Seeds that can be dried and frozen are suitable for storage at the National Center for Genetic Resources Preservation in Fort Collins, Colorado.
Finally, the project seeks not only to establish corridors and stepping stones, but to research their effectiveness in supporting the maintenance and recovery of endangered plant species. We will utilize a variety of scientific methods to monitor the success of plantings to determine ways that such connections may make a difference for the pine rocklands. It is our hope that these efforts will ultimately lead to a brighter future for the rare plants found in this habitat.
References:
Anderson, A.B., & Jenkins, C.N. (2006). Applying nature’s design: Corridors as a strategy for biodiversity conservation. New York: Columbia University Press.
Damschen, E.I., Haddad, N.M., Orrock, J.L., Tewksbury, J.J., & Levey, D.J. (2006). Corridors increase plant species richness at large scales. Science. 313, 1284-1286. Defenders of Wildlife (1991). Landscape linkages and biodiversity. (Ed. Hudson, W.). Washington, D.C.: Island Press.
Florida Natural Areas Inventory and Florida Department of Natural Resources (February, 1990). Guide to the Natural Communities of Florida. Found at: http://www.fnai.org/PDF/Natural_Communities_Guide.pdf May 16, 2008. Maschinski, J., J. Possley, M.Q.N. Fellows, C. Lane, A. Muir, K. Wendelberger, S. Wright, and H. Thornton. (2005). Using Thinning as a Fire Surrogate to Improve Native Plant Diversity in a South Florida Pine Rockland Habitat. Ecological Restoration 23: 116-117.
Miami-Dade Parks and Open Space System Master Plan (December, 2007). Found at: http://www.miamidade.gov/greatparksummit/library/OSMP_FINAL_REPORT_entiredocument.pdf August 22, 2008.
Acknowledgements:
This work is funded by U.S. Fish and Wildlife Service Grant Agreement 401817G060 and Florida Department of Agriculture and Consumer Services Division of Plant Industry Contract #013925. We thank our collaborators at The Institute for Regional Conservation, Miami-Dade County Natural Areas Management and Environmentally Endangered Lands Program.
Authors Affiliations:
Scott Lewis, Ph.D. – Field Botanist, Fairchild Tropical Botanic Garden
Joyce Maschinski, Ph.D. – Conservation Ecologist, Fairchild Tropical Botanic Garden
Figure 7 – Germination trials of Dalea carnea have been conducted by Don Walters. Photo by Don Walters.
Above: Figure 5 – Section of Miami-Dade County showing potential corridor connections along canal banks and bikeways to parks. Map developed by Karen Minkowski, Keith Bradley and George Gann.
South Dade Park
SWFMD Canal
Seminole Wayside Park
North South Bikeway
Figure 6 –High school students helping clean out duff in park. Photo by Joie Goodman.
Recent Developments Boost Recovery Prospects of Florida Ziziphus
Carl W. Weekley
The discovery in 2007 of five new populations of Florida ziziphus is the most important development for the recovery of this critically endangered Lake Wales Ridge endemic since its initial rediscovery more than 20 years ago. New populations and experimental introductions have boosted the recovery prospects of this state- and federally listed shrub. To appreciate the significance of these recent developments, it helps to know something about the unusual history and biology of Florida ziziphus.
Once thought to be extinct and later seemingly destined for extinction, is there new hope for one of Florida’s rarest and most imperiled plants?
The rediscovery of a long-lost plant and Pleistocene refugee
When a 37-year old specimen of a thorny plant with little yellow-green flowers demurely occupying an herbarium drawer at the University of Florida was given the scientific moniker Ziziphus celata by Walter Judd and David Hall in 1984, they had every reason to believe that the specimen represented a plant long-ago extinct (Judd and Hall 1984). The specimen had been collected by amateur botanist Ray Garrett in 1948, but apparently no one had seen the species since. In 1987, however, Kris Delaney, a self-described “botanical explorer”, rediscovered Florida ziziphus a few inches outside a newly-acquired state property (Delaney and Wunderlin 1989). By 2001, eight other small populations had been found, all along a 40-mile stretch of central Florida’s Lake Wales Ridge.
A species teetering on the brink of extinction
A fascinating footnote to the scientific naming of Florida ziziphus is that its closest living relative appears to be Z. parryi, endemic to Baja California (Mexico) and southern California. Like the Florida scrub-jay, several reptiles, and some other plants, the ancestor of Florida ziziphus seems to have arrived in Florida a few million years ago when arid habitats stretched eastward across the Gulf states from the Sonoran Desert. Subsequent climate changes stranded these species on the xeric uplands of Florida’s central ridges, which remained high and dry during Pleistocene sea level rises.
Although the rediscovery of Florida ziziphus was good news, its prospects for survival seemed bleak. The one population on a publicly protected site was in catastrophic decline. Most populations occupied privately owned pastures, where they could be wiped out by landowners subject to none of the rules that safeguard federally listed animals. Even robust populations produced no fruits, suggesting that plants were reproductively impaired, genetically depauperate, or both. The question seemed inescapable: had Florida ziziphus been named for science only as the prelude to its extinction?
Florida ziziphus, a thorny, multi-stemmed clonal shrub to 6 feet in height, is narrowly endemic to yellow sand xeric uplands on the Lake Wales Ridge. The pasture sites occupied by most populations once supported endemic-rich longleaf pinewiregrass sandhills. Early on, genetic research showed that remnant populations of Florida ziziphus generally comprise single genetic individuals (Godt et al. 1997, Weekley et al. 2002), although each clone may be represented by dozens of separate plants.
Mature plants flower profusely. The tiny flowers – four would fit neatly on the face of a nickel – are bisexual, with both male and female reproductive structures. On a bright January morning –the height of flowering season – you can smell the flowers from several feet away and plants hum with visiting insects. To no purpose, however, since hundreds of experimental hand-pollinations have demonstrated that Florida ziziphus is self-incompatible (Weekley and Race 2001). Because most populations comprise a single genetic individual, they are incapable of producing viable seeds.
In addition, research has shown that many genotypes are also cross-incompatible because they belong to the same mating type (Weekley et al. 2002). The number of mating types is genetically determined by the number of self-incompatibility (S-) alleles. To date, only three S-alleles have been confirmed for Florida ziziphus, the minimum number a species can have and still be capable of sexual reproduction. The isolation of remnant
Far left: Florida ziziphus fruits on a plant in Bok Tower Gardens planting bed; fruit being processed for germination trials.
Photos by C. Weekley.
Left: Newly opened Florida ziziphus flowers with anthers enclosed in clasping white petals which will reflex within 1 to 2 hours. Photo by Archbold Biological Station Plant Ecology Lab.
The discovery of five new populations of
Florida
ziziphus in 2007 radically transformed its recovery prospects by tripling the number of wild genotypes.
populations and their lack of genetic diversity are major obstacles to the recovery of Florida ziziphus.
A key attribute of Florida ziziphus’ mating system is that for each new S-allele the number of mating types increases dramatically. For example, if the number of S-alleles doubles from the currently known three alleles to six, the number of mating types will quintuple from three to 15, thereby increasing the genetic variability of resulting offspring. Increased genetic variability provides a significant hedge against extinction and allows populations to adapt to changing environmental conditions. The discovery of populations representing novel genotypes and mating types is thus critical to the recovery of Florida ziziphus.
Prior to 2007, only a dozen genotypes and two S-locus mating types had been identified in the nine known wild populations of Florida ziziphus. Fortunately, by the mid-1990s, a captive population at Bok Tower Gardens, which includes most of the wild genotypes, began producing a large fruit crop annually. This meant that the species retained the capacity for sexual reproduction. It also meant that viable populations could be created by planting compatible genotypes in close enough proximity to permit outcrossing.
Genetic advances
Dr. Matt Gitzendanner and his colleagues at the Florida Museum of Natural History’s Laboratory of Molecular Systematics and Evolutionary Genetics have recently identified additional genetic variation within some of the pre-2007 populations and confirmed the existence of the third S-locus mating type, long hypothesized on theoretical grounds. The Genetics Lab has now shown that the only pre-2007 wild population that produces viable fruit contains at least four distinct genotypes. Earlier evidence suggesting that this population comprised a single genetic individual did not square with Florida’s ziziphus’ self-incompatible mating system.
Recent genetic results also show that some of the plants in the captive population in the Bok planting beds are seedlings rather than clonal root shoots of nearby plants, as previously thought. High stem density within the Bok beds makes it difficult to collect fruits and to ascertain the origin of new recruits. The appearance of seedlings in the Bok planting beds is welcome news because seedlings increase the genetic diversity of the captive population and provide an opportunity for investigating backcrosses between offspring and their parental plants.
In addition, Matt and his co-workers have now confirmed that some of the flowering plants in the captive population constitute a third S-locus mating type. This finding was not surprising since half of the offspring from crosses between the two known wild mating types should result in genotypes representing a third mating type. The third mating type has not been found in the wild, but it is a satisfaction to get its existence confirmed. Mating type III plants should be able to backcross with both parental mating types and will play an important role in the recovery of Florida ziziphus.
Creating new populations
The establishment of genetically diverse and sexually reproductive populations on appropriate conservation lands is the central goal of the Florida ziziphus recovery plan (USFWS 1999). Since 2002, plant conservationists from several agencies and institutions (including Archbold Biological Station, Bok Tower Gardens, the Florida Division of Forestry, and The Nature Conservancy) have collaborated on six translocation projects. Three projects were genetic augmentations involving the addition of new genotypes
Above: Large Florida ziziphus plant in planting bed at Bok Tower Gardens. Photo by C. Weekley.
to sites occupied by a uniclonal population. The goal of these augmentations is to provide enough genetic variation that the population becomes capable of sexual reproduction. Three other projects were introductions, the translocation of plants representing multiple genotypes to sites not previously containing a Florida ziziphus population. Altogether, these projects included over 600 potted plants and almost 6000 seeds.
The first hurdle in the translocation of species is transplant survival. Florida ziziphus transplants have handily met the challenge. In most of the six projects, cumulative transplant survival is greater than 70% after several years, and introduced populations are persisting in the face of the usual vagaries of Florida’s climate, including the severe droughts of the last two years (winter-spring droughts of 2007 and 2008). The ultimate measure of the success of these translocations is the production by introduced plants of viable offspring.
New discoveries brighten future for Florida ziziphus
The discovery of five new populations of Florida ziziphus in 2007 radically transformed its recovery prospects by tripling the number of wild genotypes from 12 to 38. The two largest populations, comprising over 600 plants and at least 21 new genotypes, were discovered in pasture sites near Lake Wales by Cindy Campbell, Curator of Endangered Plants at Bok Tower Gardens. Together, these two populations, which are separated by only a few hundred yards, more than double the number of plants –and, more importantly, the number of genotypes – known from the wild. A few weeks later, three other new populations were discovered. Plant conservationists Roy Stewart and Brett Miley independently found two new populations on state lands and researchers from Archbold Biological Station found a third. Although these three populations encompass fewer than 40 plants, they represent at least four additional genotypes. Plants in all five of the new populations flowered heavily in 2008, but only one produced a significant fruit crop. Over
a third of the plants in the Lake Wales South Pasture site flowered, yielding a combined crop of over 1800 fruits, thereby indicating that the site contains at least two cross-compatible mating types. The relationship of these mating types to the three previously confirmed mating types has not yet been determined. It is likely, however, that at least some of the new genotypes also represent novel mating types.
Conservation of the 21 new genotypes encompassed by the two large Lake Wales Ridge pasture populations is critical to the recovery of Florida ziziphus. This goal can be accomplished either by public acquisition of the sites or by clonal propagation of the genotypes for inclusion in captive population at Bok. Both routes are currently being pursued.
Although it is too soon to fully assess the impact of these recent discoveries on the recovery of Florida ziziphus, they inspire a renewed confidence that this ancient shrub will have a future as fascinating as its past.
Literature cited
DeLaney, K.R., R.P. Wunderlin, and B.E. Hansen. 1989. Rediscovery of Ziziphus celata (Rhamnaceae). Sida 13:325-330.
Godt, M.J.W., T. Race, and J.L. Hamrick.1997. A population genetic analysis of Ziziphus celata, an endangered Florida shrub. The Journal of Heredity 88:531-533.
Judd, W.S., and D.W. Hall. 1984. A new species of Ziziphus (Rhamnaceae) from Florida. Rhodora 86:381-387.
US Fish and Wildlife Service. 1999. Florida Ziziphus. In: Multi-Species Recovery Plan for the Threatened and Endangered Species of South Florida. US Fish and Wildlife Service, pp. 1986-1999. Atlanta, GA.
Weekley C.W. and T. Race. 2001. The breeding system of Ziziphus celata Judd and D. Hall (Rhamnaceae), a rare endemic plant of the Lake Wales Ridge, Florida. Biological Conservation 100:207-213.
Weekley, C.W., T.L. Kubisiak, and T.M. Race. 2002. Genetic impoverishment and cross-incompatibility in remnant genotypes of Ziziphus celata (Rhamnaceae), a rare shrub endemic to the Lake Wales Ridge, Florida. Biodiversity and Conservation 11:2027-2046.
Above left: (pictured left to right) Katrina Holten and Regan Rich of Bok Tower Gardens and Eric Menges of Archbold Biological Station harvest Florida ziziphus fruits from a newly discovered Lake Wales pasture population. Above right: (pictured left to right) Gretel Clarke (in background), Lauren Sullivan and Stacy Smith of Archbold Biological Station planting Florida ziziphus seeds in 2007 introduction at Tiger Creek Preserve. Photos by C. Weekley.
Tamarindillo or Cinnecord Acacia choriophylla (LEGUMINOSAE)
by Daniel B. Ward
The Tamarindillo or Cinnecord (Acacia choriophylla Benth.) has been known to occur in Florida ever since its discovery on Key Largo by Taylor R. Alexander in 1967 (reported in 1968). By some it has been assumed to be native, by others it has been dismissed as an introduction. The determination as to its correct status rests in part on the known facts of its distribution, and in part on one’s interpretation of these facts.
Acacia choriophylla is a small tree, without spines. The leaves are twice-compound, with each leaf having 3-5 pairs of pinnae. The leaflets are entire, elliptic, and rather leathery. Flowers are yellow and are produced in small dense spherical heads. Fruits are flattened woody pods, each bearing 2-3 seeds. (Illustration - Ward, 1979.) In the Bahamas, its natural home, it is common (“almost ubiquitous” – Correll & Correll, 1982), often found aggressively invading newly exposed soils and construction sites.
A plant defined as “native” must be one that is believed to have been present in Florida prior to the dramatic biogeographic (and cultural!) shock of European incursion (Ward, 2003). Though this point of demarcation need not be defined precisely in terms of an exact year, no other event in the state’s history is as feasible in dividing the state’s flora into the useful categories of native vs. introduced.
At first glance, a plant unknown in Florida prior to Alexander’s 1967 discovery may be assumed to be new to the state, and thus an introduction. But on reflection, the considerable number of new species encountered in recent years must be formed both of species newly arrived, and of species long present but previously overlooked. The task here is to determine to which of these categories Acacia choriophylla belongs.
The legal status of Acacia choriophylla is unambiguous. On the basis of Alexander’s report, in 1978 it was assigned the rank of “endangered” by the Florida Committee on Rare and Endangered Plants and Animals (Ward, 1979). This ranking was accepted in 1980 by the then-newly-formed
Endangered Plant Advisory Council (EPAC) of the Florida Department of Agriculture and, through the Department’s rule-making power, now has the protection of law. Florida Statute 581.185 (the “Rare Plant Law”) specifies that only native plants may be considered for listing. The Council follows the policy of periodically reviewing its rankings, and has twice (in 1992 and again in 1999) re-examined the nativity of Acacia choriophylla. Though strong arguments have been made to the Council to reverse
Acacia choriophylla – Photo by T. Ann Williams
its previous findings, the Department has not acted in this regard. Acacia choriophylla thus is legally considered a native species.
The biological basis for treating the plant as native is far less clear. Alexander (1968) found only a single plant on north Key Largo, a tree already windthrown but with vigorous erect shoots and a main trunk 12 to 16 cm. in diameter. The site was remote, originally selected for study because of its “apparent freedom from interference by man in recent times.”
This individual was destroyed by fire in 1975. In 1977 Alexander found a second tree in the same area, but this too apparently disappeared soon after. About 1975 Ann Williams found a 10 to 12 ft. tree on a Sugarloaf Key canal spoilbank, and a second one in an adjacent yard. In 1981 George Avery was shown what may have been the tree known to Williams; it was then 3 m. tall, with a trunk 31 cm. in diameter (could Avery have meant “circumference”?).
Soon after Avery’s observation the tree was removed by a developer. At least one new observation was of a direct import; a large tree in a north Key Largo dooryard originated with seed brought from the Bahamas about 1960, as reported by its owner to Roger Hammer. Other trees, outside of cultivation, some described as “large,” have since been encountered at Cape Florida State Park on Key Biscayne, at the Deering Estate on Cutler Ridge, and on West Butternut Key in Florida Bay, in Little Hamaka Park, Key West. Small plants have been seen at various locations on Big Pine Key. Most of these different individuals were destroyed by development or by natural forces (Hurricane Andrew in 1992 blew down the Deering Estate and Cape Florida specimens) or simply disappeared. New plants, however, have continued to be found. Yet at no location was there a report of a natural, self-sustaining population.
None of the early observers encountered Acacia choriophylla in cultivation. But after the plant was officially designated as “endangered,” the Key West Botanical Garden began distribution of seedlings, now grown into small trees throughout South Florida.
It is thus clear that, within the last half century at least, Acacia choriophylla repeatedly appears “out in the middle of nowhere” (Ann Williams, pers. comm., Mar 1999), then vanishes without establishing viable populations. This pattern is consistent with a species whose fruits/seeds are capable of surviving water-borne transport (Alexander suggested bird-transport), yet are self-sterile. There is no reason to assume chance introductions from the Bahamas are limited to historic times. The question then arises: Is a plant native if it is repeatedly introduced by natural forces, perhaps over the millennia, even though the recent introductions long post-date European influence? That is, is it necessary if a species is to be considered native, that individuals present
today must be the lineal descendants of plants present in the state in pre-Columbian times? Or is it possible for a species to be considered native if the facts of its appearance indicate a natural mode of introduction and probable long-standing presence in the state, though no present individual is of ancient genetic lineage?
Obviously there is no “right” answer. The lack of populations that are self-sustaining through sexual reproduction strongly suggest that individual propagules – viable seeds, presumably – are repeatedly introduced into the state. The absence of the species in cultivation, until recent years at least, excludes domestic plants as a source. The abundance of the plant in the Bahamas and the ease of water-borne transport removes concern for a possible seed reservoir. Yet the clear discontinuity of genetic lines within the state requires a distortion of the standard definition of “native” if this species is so treated.
There is, however, a political aspect to this issue. Though one cannot advocate a dogged adherence to a position that is clearly factually in error, that is not the case here. Indeed a case can be made that the plant is truly native, that surely individuals of the species have been here from time immemorial, and that the probable break in their genetic lines cannot discredit their native status. The plant has been assumed to be native since 1979, has had that imprimatur placed upon it by the State of Florida, and is now distributed and grown under that assumption. The plant in Florida wildlands is indeed rare, the plant in cultivation is distinctive and attractive, and there is naught to be gained by challenging its present status.
I wish to acknowledge Taylor Alexander for his early reports both published and verbal, Ann Williams and especially Roger Hammer for their detailed documentation of distribution within southern Florida, Carol Lippincott for her observations of the plant in the Bahamas, and Richard Abbott for his penetrating comments on the manuscript.
References Cited
Alexander, T. R. 1968. Acacia choriophylla, a tree new to Florida. Quart. J. Florida Acad. Sci. 31:197-198.
Correll, D. S. & H. B. Correll. 1982. Flora of the Bahama Archipelago. J. Cramer, Vaduz. 1692 pp.
Ward, D. B., ed. 1979. Rare and Endangered Biota of Florida. Vol. Five: Plants. Univ. Presses of Florida, Gainesville. 175 pp.
Ward, D. B. 2003. Native or Not: Studies of problematic species. No. 1: Introduction. Palmetto 22(2):7-9.
About the Author
Dr. Dan Ward is Professor Emeritus at the University of Florida.
Florida Native Plant Society Annual Report
for the Years Ended December 31, 2006 and December 31, 2007
Statement of Functional Expenses
Statement of Cash Flows
Independent Accountant’s Report
August 29, 2008
To the Board of Directors of Florida Native Plant Society,
I have audited the accompanying statements of financial position of Florida Native Plant Society (a non-profit organization) as of December 31, 2007 and 2006, and the related statements of activities, cash flows, and functional expenses for the years then ended. These financial statements are the responsibility of the Organization’s management. My responsibility is to express an opinion on these financial statements based on my audit.
I conducted my audit in accordance with auditing standards generally accepted in the United States of America. Those standards require that I plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatements. An audit includes examining, on a test basis, evidence supporting the amounts and disclosure in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. I believe that my audit provides a reasonable basis for my opinion.
In my opinion, the financial statements referred to above present fairly, in all material respects, the financial position of Florida Native Plant Society as of December 31, 2007 and 2006, and the results of its activities, cash flows, and functional expenses for the years then ended in conformity with accounting principles generally accepted in the United States of America.
Ella W. Boll, CPA, P.A.
Certified Public Accountant
Statement of Activities
Travel Especially for FNPS Members Ecology and Native Flora of Nicaragua
This July join us for an exciting trip to Nicaragua. Latin American Adventures LLC has designed a unique adventure for FNPS members, with plenty of opportunities to view plants and animals in Nicaragua’s protected reserves.
Experience the Volcán Mombacho Cloud Forest, 850 meters above sea level. Travel by boat to Isla de Zapatera – an island preserve for virgin tropical dry and wet forests, where in addition to plants we will view ancient petroglyphs. Discover Los Guatuzos Wildlife Preserve, home to tropical wetlands, rainforest and myriad species of animals. For a complete itinerary, lodging information and details on more of the locations we will visit, go to www.fnps.org.
Nicaragua: Land of Lakes and Volcanoes
Trip Dates:
July 16 – 28, 2009
Elston Raimundo Chavarria 2526 NW 99th Avenue, Coral Springs, FL 954-662-1539 ● raimundochavarria@yahoo.com www.latinamericanadventuresllc.com
FNPS Chapters and
Representatives
For chapter contact information, visit www.fnps.org. Go to Join FNPS and click on the Find a Chapter link.
1. Citrus ...........................Jim Bierly.....................................jbierly@tampabay.rr.com
2. Coccoloba ....................Dick Workman..............................wworkmandick@aol.com
3. Cocoplum .....................Sherry Friend ...............................blighia@aol.com
4. Conradina ....................Vince Lamb ..................................vince@advanta-tech.com
5. Coontie ........................Kirk Scott ....................................kirkel1@yahoo.com
6. Dade ............................Lynka Woodbury...........................lwoodbury@fairchildgarden.org
7. Eugenia ........................Sue Thompson .............................susandjesse@bellsouth.net
8. Heartland .....................Amee Bailey .................................ameebailey@polk-county.net
9. Hernando .....................Jim Clayton ..................................geoska10@hotmail.com
10. Ixia ...............................Jake Ingram .................................jakeingramla@comcast.net
11. Lake Beautyberry .........Peg Lindsay..................................pegcondor@embarqmail.com
12. Lakelas Mint ................Royce Sisson................................roycesisson@hotmail.com
13. Longleaf Pine ...............Amy Hines....................................amy@sidestreamsports.com Cheryl Jones ................................wjonesmd@yahoo.com
14. Lyonia ...........................David Schroeder...........................evolvinglandscapes@yahoo.com
15. Magnolia ......................Ann Redmond ..............................aredmond@mindspring.com
16. Mangrove .....................John & Christine Holyland ...........christineholyland@comcast.net
17. Marion .........................Robin Caple .................................robincaple@comcast.net
18. Naples .........................Ron Echols ...................................preservecaptains@aol.com
19. Nature Coast ................Susan Vaughn ..............................vaughn_s@firn.edu
20. Palm Beach ..................Lynn Sweetay...............................lynnsweetay@hotmail.com
21. Pawpaw .......................Elizabeth Flynn .............................eliflynn@cfl.rr.com
22. Paynes Prairie ..............Heather Blake ..............................butterflygirlh@yahoo.com
23. Pine Lily .......................Christina Uranowski .....................curanowski@aol.com
24. Pinellas ........................Debbie Chayet..............................dchayet@verizon.net
25. Sarracenia ...................Lee Norris ....................................lnorris@ectinc.com
26. Sea Oats ......................Cindy Maguire ..............................Maguire122@aol.com
27. Sea Rocket ..................Paul Schmalzer ............................paul.a.schmalzer@nasa.gov
28. Serenoa .......................Dave Feagles ...............................feaglesd@msn.com
29. South Ridge .................Karina Veaudry .............................executivedirector@fnps.org
30. Sumter .........................Anne M. Lambrecht ......................annel@thevillages.net
31. Suncoast .....................Kristina Herz ................................heartkh@gmail.com
32. Sweet Bay ...................Robert Silverio..............................bonsaibob@comcast.net
33. Tarflower ......................Jackie Rolly..................................j.y.rolly@att.net
The Florida Native Plant Society PO Box 278 Melbourne FL 32902-0278
Non-Profit Organization U.S. POSTAGE PAID Jacksonville FL PERMIT NO. 877