Volume 31: Number 3 > 2014

The Quarterly Journal of the Florida Native Plant Society Palmetto

Rare Plant Conservation at Bok Tower Gardens ● Yaupon Redeemed ● The Origin of Florida Scrub Plant Diversity Donna Bollenbach and Juliet Rynear

A Collaboration of Passion, Purpose and Science Bok Tower Gardens Rare Plant Conservation Program

“Today nearly 30 percent of the native fl ora in the United States is considered to be

1 of conservation concern. Without human intervention, many of these plants may

be gone within our lifetime. Eighty percent of the at-risk species are closely related

to plants with economic value somewhere in the world, and more than 50 percent

are related to crop species...but it can be saved.”

– Center for Plant Conservation

Ask the average Florida citizen to name at least one endangered native animal in the state and they will likely mention the Florida manatee or the Florida panther. Ask the same person to name one endangered native plant and they give you a blank stare. Those of us working to conserve Florida’s unique plant species know this all 2 too well, and if the job isn’t diffi cult enough, a lack of funding and support for the conservation of land supporting imperiled plant communities makes it harder. Bok Tower Gardens Rare Plant Conservation Program is one of 39 botanical institutions throughout the United States that collaborate with the Center for Plant Conservation (CPC) to prevent the extinction of native plants in the United States. Created in 1984, CPC institutions house over 750 living specimens of the nation’s most endangered native plants, the largest living collection of rare plants in the world. According to the CPC, fi ve percent of all native fl ora is on or qualifi es for the federal endangered species list, and Florida is the No. 3 hotspot for critically imperiled plant diversity (CPC, n.d.). Of the 64 rare Central and North Florida plants under curation at the Bok Tower Gardens Rare Plant Conservation Program, 29 are federally-listed and 35 are state-listed as endangered or threatened native fl ora (Bok Tower Gardens n.d.). Like endangered animals, native plants are threatened by increased develop- 3 ment, fi re suppression in fi re-adapted communities, habitat destruction and invasive Continued on page 6

Photos: 1. Bok Tower 2. Ziziphus celata 3. Bonamia grandifl ora 4. Juliet Rynear in the greenhouse 5. Rare Plant Conservation Program National Collection Beds at Bok Tower Garden 6. Monitoring Warea amplexifolia 7. Imperiled scrub plant rescue 8. Clitoria fragrans 9. Conradina etonia 10. Conradina glabra 11. Dicerandra frutescens 12. Chrysopsis fl oridana. Photos 1, 2, 3 ,5, 10, 12 – Donna Bollenbach; 4, 8, 9, 11 – Joel Jackson; 6, 7 – Juliet Rynear.

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10 11 12 A Collaboration of Passion, Purpose and Science (continued from page 4) species. However, more legal protections Partial List of Plants in the National Collection Monitored by Bok Tower Gardens exist for endangered animals because they are considered public property, Scientific Name Common Name(s) whereas plants are considered private Asimina tetramera four-petal pawpaw property. Except for commercial pur- Bonamia grandiflora scrub morning-glory, large-flowered bonamia, Florida bonamia poses, private landowners can remove Calamintha ashei Ashe’s savory or destroy rare plant populations on their Calamintha dentata toothed savory Chionanthus pygmaeus pygmy fringe-tree property without a permit. This lack of Chrysopsis floridana Florida goldenaster protection for plants is rooted in British Clitoria fragrans scrub pigeon-wing Common Law, which was adopted by Conradina canescens short-leaved rosemary the American legal system. Under Conradina etonia etonia rosemary Common Law, animals belong to the Conradina glabra Apalachicola rosemary government, but plants belong to the Conradina grandiflora large-flowered rosemary landowner, so private landowners can Crotalaria avonensis Avon Park harebells, Avon Park rabbit-bells destroy protected plants with impunity Cucurbita okeechobeensis Okeechobee gourd and the government cannot intervene. Cuphea aspera tropical wax weed CPC institutions, such as Bok Tower Deeringothamnus rugelii var. pulchellus white squirrel-banana, beautiful pawpaw Gardens Rare Plant Conservation Program Deeringothamnus rugelii Rugel’s pawpaw, yellow squirrel-banana work to overcome this inequity. Native Dicerandra christmanii Garrett’s mint, Christman’s dicerandra Dicerandra cornutissima longspurred balm, longspurred mint plants, defined by the CPC as those that Dicerandra frutescens scrub balm, scrub mint have been growing in our state before Dicerandra immaculata var. savannarum Lakela’s mint human settlement (CPC n.d.), provide Eryngium cuneifolium snakeroot, wedge-leaved button-snakeroots, wedge-leaved eryngo us with food, medicines, fuel, flavor, Euphorbia telephioides telephus spurge fragrance, beauty and so much more. Harperocallis flava Harper’s beauty They are intrinsic to our survival and scrub hypericum, highlands scrub St. John’s-wort, Hypericum cumulicola our quality of life. Each time we allow highlands scrub hypericum a plant to go extinct we are not only Justicia pringlei Cooley’s water-willow, Cooley’s justicia destroying a part of our heritage, but a Liatris ohlingerae Florida gay-feather, scrub blazingstar possible cure for a disease or a valuable Liatris provincialis Godfrey’s blazing-star food source. It is this knowledge and Lupinus westianus var. aridorum scrub lupine Macbridea alba white birds-in-a-nest passion for native plants that drives Matelea alabamensis Alabama anglepod, Alabama spiny-pod the Rare Plant Conservation Program Nolina brittoniana Britton’s bear-grass and countless volunteers to spend hours Paronychia chartacea papery whitlow-wort, paper-like whitlow-wort in the scorching Florida sun rescuing, Polygala lewtonii Lewton’s polygala restoring and monitoring imperiled Polygonella basiramia wireweed native plant populations. Polygonella macrophylla large-leaved jointweed To understand the work of the CPC Prunus geniculata scrub plum one has to understand the science behind Spigelia gentianoides gentian pinkroot it. The goal of any conservation program Warea amplexifolia clasping warea, wide-leaf warea is to protect and restore biodiversity. Warea carteri Carter’s mustard, Carter’s pinelandcress, Carter’s warea Biodiversity is defined as the variety of life Ziziphus celata Florida ziziphus, ancient ziziphus on Earth. On a large scale, biodiversity includes the variety of living organisms Thus, when creating procedures to to consider the natural community of within ecosystems, or landscapes, in the collect plant material for the propaga- each species, its historical range, the world, such as deserts, rainforests, wetlands tion and reintroduction of rare plants, potential for outbreeding or inbreeding and scrub, to name only a few. On a smaller CPC institutions partner with scientists, depression, hybridization with closely scale, biodiversity is measured at the mo- government agencies, private and public related congeners, and the condition lecular level within the genes of individual landowners, and concerned citizens to of each introduction site (level of fire plants and plant populations. The greater develop protocols that are designed suppression and impact of invasive species). the genetic diversity within a population, to protect and conserve the unique Hybridization is the exchange of the more likely it will be that the popula- genetic diversity within our native plant genetic material (or interbreeding) of tion will survive long into the future. populations. To do this, partners need different species or genetically dissimilar

6 ● The Palmetto Volume 31:3 ● 2014 individuals from the same species plants are transplanted into specially (Wittler 2014). While biologists agree prepared beds within the National that some hybridization occurs naturally Collection or hardened-off in the nursery in the course of evolution, and is some- until they can be reintroduced to a pro- times beneficial, rampant hybridization tected site. The living specimens within that results from the introduction of the National Collection are used for invasive species (including the movement research or cloned by root and/or stem of native species outside their historical cuttings to use for population introduc- range) is a threat to biodiversity. These tions onto protected sites. Only shoots man-made events, which bring two previ- or cuttings are used to clone some spe- ously isolated species of the same genera cies because their seeds are very prone into contact, can result in genetic swap- to hybridizing with similar species in ping that, more often than not, results in the nearby plant beds or in the wild. The a weaker, less fit plant, or one that is in- staff keeps meticulous records. Seeds fertile. According to Donald Levin in his collected from the wild are accessioned article Hybridization and Extinction, “Most and tracked in a database and every hybrids are inferior to their parents. Some plant or clone in the greenhouse has a abort as embryos, others die as juveniles, unique number that associates it with Juliet Rynear pointing out recently sprouted seeds taken and others still grow to adulthood, but its collection source and collection date. from refrigeration. Photo by Donna Bollenbach cannot reproduce.” (Levin, 2002). Such The permanent tags will remain with an event, often referred to as “extinction the plants for many years to allow within which the target species occurs) by hybridization,” is especially damag- researchers to continue to track the within the historical range of the species. ing to rare species coming into contact success of each population introduc- Florida’s unique biogeography and natu- with more abundant ones. Interbreeding tion by monitoring each plant’s health, ral history has given rise to many unique between a rare and prolific species can growth and reproduction. native plant communities that evolved eventually create a hybrid that displaces The task of finding suitable pro- on isolated islands during interglacial the native population. tected locations to reintroduce rare periods when sea level was much higher Extinction by hybridization can plant populations into the wild falls on than it is today. This isolation led to a also work another way. If one species is the local institutions in collaboration high degree of endemism (plants occur- defined by features that are homozygous with the U.S. Fish and Wildlife Service ring only in Florida). At the present time, recessive alleles, then hybridization with and other federal, state, and local public there are 29 federally-listed endemic plant a closely related species that features agencies. In Florida, that task is becom- species in the Florida scrub community dominant alleles for those particular ing increasingly difficult as the last alone. Further, some species are adapted features can quickly mask the characters remaining parcels of intact, imperiled to specific microhabitats within a plant that define the recessive species. natural communities are being devel- community (Hartnett and Richardson The threat of undesired hybridization oped for housing, roads and planned 1989; Menges et al. 1999; Richardson must also be avoided when introducing communities. For example, some of et al. 2014). rare plant populations. The CPC and its the last remaining parcels of scrub In addition to finding a location that institutions, such as Bok Tower Gardens habitat on the Mount Dora Ridge occur meets the growing requirements of the Rare Plant Conservation Program, perform in small city parks. plant, conservation professionals must much needed research to develop success- According to the CPC, “Tasks like consider what other plants are growing ful protocols needed to propagate rare plant identifying and managing threats, plan- in the surrounding areas. If the habitat species, introduce rare plants back into ning or implementing habitat restoration is in reproductive proximity to a popula- the wild, and to establish new rare plant actions, restoring the plant populations tion of either native or non-native plants populations onto protected sites. The themselves, fine tuning land management in the same genera that may hybrid- institutions follow strict scientific proto- practices, and planning for future mainte- ize with the introduced populations, cols created by the CPC when collecting nance are actions at the community level they must rule out that habitat. Once seeds and cuttings from existing plant that require a good functional under- a suitable location has been chosen populations so as to protect existing wild standing of the habitat type” (CPC 2006). and a population has been successfully populations. Living plants are rescued At the start of each project, conser- introduced, scientists must continue to from the wild when development of a site vation partners look for suitable habitat monitor the population for many years is imminent and assured. The rescued (the natural community or communities to document long-term viability.

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Volume 31:3 ● 2014 The Palmetto ● 7 A Collaboration of Passion, Purpose and Science (continued from page 7)

Recovering im- periled native plants in the U.S. is a long process. It may take scientists and researchers decades to develop success- ful methods for seed The Palmetto (ISSN 0276-4164) Copyright 2014, Florida Native Plant Society, all banking, germina- rights reserved. No part of the contents of this magazine may be tion, propagation, reproduced by any means without written consent of the editor. The Palmetto is published four times a year by the Florida Native Plant and introduction Society (FNPS) as a benefit to members. The observations and opinions expressed in attributed columns and articles are those of the back into the wild. respective authors and should not be interpreted as representing the They must consider official views of the Florida Native Plant Society or the editor, except the life history of Conradina etonia. Photo by Joel Jackson. where otherwise stated. each species (lifespan, Native plant conservation is im- breeding system, seed dispersal mecha- portant in our state, our country and nism, etc.) and the conditions that the around the world. Bok Tower Gardens plants are exposed to in the wild. Long- Rare Plant Conservation Program is term seed storage may allow reintroduc- part of a global network involved in tion of the species if it disappears in the projects with government agencies, wild. Most seeds are dried to 15%-20% universities, research institutes, con- moisture content and then stored at CPC servation organizations and private institutions, such as Bok Tower Gardens, landowners that dedicate their work or in cryogenic, long-term storage at the to ensuring that our treasured native National Center for Genetic Resources plants will thrive for many generations Preservation in Fort Collins, Colorado. to benefit from and enjoy.

Literature Cited compound the more well-known threats to wildlife. American Scientist, v90, i3 p 254(9). Bok Tower Gardens. (n.d.) Rare Plant Conservation Program. [Online] Available: http://boktowergardens. Menges, E.S., McIntyre P.J., Finer M.S., Goss E., org/conservation/national-collection Yahr R. 1999. Microhabitat of the narrow Florida scrub endemic Dicerandra christmanii, with Center for Plant Conservation. 2006. Plant Conservation comparisons to its congener D. fructescens. Newsletter, Spring 2006, V19, No. 1: Pages 8, 9,11 Journal of the Torrey Botanical Society 126:24–31 [Online] Available:http://www.centerforplantconserva- tion.org/News/Newsletter/Spring2006.pdf Richardson M.L., Rynear J., Peterson C.L. 2014. Microhabitat of critically endangered Lupinus Center for Plant Conservation. (n.d.) (Introduction aridorum (Fabaceae) at wild and introduced locations to) Dancing with Extinction, Florida Special Edition in Florida scrub. Plant Ecology 215:399–410. Newsletter, Paragraph 1, [Online] Available: http:// www.centerforplantconservation.org/FL%20Spe- Wittler, G. 2014. Biology Reference. Hybridization, cial%20Edition/FL%20Special%20Edition.asp Plant. Biology Encyclopedia [Online]: Available: http://www.biologyreference.com/Ho-La/Hybridiza- Center for Plant Conservation. (n.d.) "Plant Conservation tion-Plant.html#ixzz3EKOH6S2p for Gardeners" [Online] Available: http://www.cen- terforplantconservation.org/Education/Publications/ Gardener TipSheet.pdf About the Author

Center for Plant Conservation. (n.d.) Plants in Peril, Donna Bollenbach is a Florida Master Naturalist, Top 5 Questions About Rare Plants, Para 1, [Online] Suncoast Native Plant Society board member, Friends Available:http://www.centerforplantconservation.org/ of Kissimmee Prairie Preserve board member and an Hartnett, D.C., Richardson D.R. 1989. Population avid nature photographer and writer. She loves studying biology of Bonamia grandiflora (Convovulaceae): and writing about topics important to the preservation effects of fire on plant and seed dynamics. and protection of our native flora and fauna. American Journal of Botany 76:361–369. Juliet Rynear is the Rare Plant Specialist at Bok Tower Levin, D. 2002. Hybridization and extinction: in Gardens and the Conservation Committee Chair for protecting rare species, conservationists should FNPS. She has enjoyed a life-long love of plants and consider the dangers of interbreeding, which our natural world.

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