Format: ORAL

Aaron S. David1, Sterling A. Herron1, Christine E. Edwards2, Brigette Williams2, Eric S. Menges1

1 Archbold Biological Station, Venus, FL, USA 2 Missouri Botanical Garden, St. Louis, MO, USA

Florida ziziphus (Pseudoziziphus celata (Judd D.W. Hall) Hauenschild) is a critically endangered, clonal shrub, endemic to sandhill habitat within the Lake Wales Ridge of central peninsular Florida. It was once thought to be extinct but was rediscovered in the wild in 1987 and several locations since then. Several barriers to species recover exist, including a highly restricted range, low genetic diversity, slow growth, and the presence of mating types. Since the 1990s, our comprehensive efforts to rescue the species combine demographic monitoring, ex-situ conservation, genetics, propagation, and translocation to establish new populations on protected lands. In this presentation, we will (1) report on the genetic diversity in the species and how this information is used in conservation translocation, (2) describe advances in understanding the epigenetic diversity in this species, (3) report on demographic success of the species introduction efforts. We have documented 46 genotypes in existence, and only three S-locus mating types, which severely limits cross-compatibility. DNA methylation patterns suggest a potential epigenetic basis for mating types, though further research is required. Demographic monitoring on 18 translocations established between 2002-2023 shows that the Florida ziziphus has a high survival rate but very low recruitment rate, so maintaining viable, self-sustaining populations remains a challenge. Nevertheless, strides have been made in developing germination techniques, tissue culture propagation, and best land management practices for transplant survival, especially prescribed burn management. Overall, Florida ziziphus serves as an important case study for the preservation of a highly endangered clonal species, which was brought back from the brink of extinction.