Florida ziziphus (Ziziphus celata) is one of the rarest and most imperiled plants in Florida. It is so rare that the taxonomists who named it thought they were describing an extinct species. And given its limited geographic distribution, small populations, lack of genetic diversity and reluctance to reproduce sexually, the taxonomists fear could still prove true. Florida ziziphus was named and described in 1984 from a specimen that had languished in an herbarium drawer for 36 years. No live plant was known to the taxonomists who described it (Judd and Hall 1984). But, beginning in 1987 (Delaney et al. 1989), six small populations of Florida ziziphus were discovered along a 35 mile stretch of the Lake Wales Ridge in Central Florida. Its natural habitat was probably longleaf pine/wiregrass sandhill, but today four of the six known populations are in pastures, where they have been subjected to mowing, periodic (unsuccessful) attempts at eradication, and trampling by cattle. A member of the buckthorn family (the Rhamnaceae), Florida ziziphus is a single or multi-stemmed woody shrub, 3 to 6 ft. in height. It has spiny, zigzag branches with small (less than 1 in. long) alternate leaves, shiny on their upper surface. The leaves are deciduous, falling in December before flowering begins in early January. Flowers are tiny--four fit neatly on the face of a dime--and are perfect, containing both anthers and a pistil surrounded by a nectar ring. Mature plants bloom profusely, with flowers numbering in the tens of thousands. The fragrant flowers attract legions of insects, including flower flies, bees, wasps and butterflies. Some floral visitors are quite noisy and on sunny mornings plants can be heard as well as smelled from several yards away. The fruit is a drupe about 1/2 in. in length that turns yellow as it ripens in late May. Most populations of Florida ziziphus consist of more or less distinct clumps of apparently disparate plants which, once examined genetically, turn out to be a single genetic individual (a clone). These clones are not only self-incompatibleincapable of producing offspringbut many clones are also cross-incompatible. Thus most populations do not reproduce sexually. Sterile populations can persist through vegetative growth, with new stems arising from an expanding root system, but long term viability requires the restoration of sexually-reproductive populations (Weekley et al. 1999).