An adaptive approach to translocating and augmenting the rare scrub mint to Savannas Preserve State Park, Florida, USA

Summary

Savannas mint (Dicerandra immaculata var. savannarum), a rare Florida scrub endemic discovered only in 1995 and reduced to just 81 known individuals by a 2007 survey, faces near-certain long-term loss at its sole original site due to residential development, invasive plant encroachment and fire-suppression-driven overshading, prompting Bok Tower Gardens and the Florida Park Service to translocate the species to Savannas Preserve State Park, roughly 5 km from the source population and outside pollination range of related mint species to avoid hybridization risk. Because only about five cuttings can be taken from each of the few known parent plants annually without harming the wild population, roughly 300 cuttings were collected each spring for greenhouse rooting using auxin treatments, yielding about 200 clones per year at a 50-75% propagation success rate, supplemented by another 100-200 seed-grown individuals; all reproductive structures were removed before outplanting to prevent unwanted hybridization, and plants were hardened outdoors before transplanting with hydrating gel and initial irrigation. Annual monitoring timed to peak November flowering found 51% survival among initial plantings, with 83% of survivors flowering or setting seed, and 67 new wild-germinated seedlings detected within a year, though long-term self-sustainability remains to be confirmed as the seed bank develops. Major difficulties included obtaining private landowner permission for wild collection, insufficient new growth for cuttings during drought years, limited knowledge of the species' historic range, and continued development pressure on the source population. The project rates itself Successful, crediting strong interagency collaboration and the species' inherent vigor for the encouraging early survival, flowering and recruitment results.