Research Spotlight: March 2016

Using Herbarium specimen data to understand native mint distribution, evolution, and ecology  

-- Contributed by Andre Naranjo

I am a graduate student at the University of Florida, and a member of the Soltis Lab, working on a genus of scrub mints found only in the southeastern United States. Dicerandra, in the mint family (Lamiaceae) comprises ten endemic species, namely Dicerandra christmanii, D. cornutissima, D. densiflora, D. frutescens, D. fumella, D. immaculata, D. linearifolia, D. modesta, D. thinicola, D. radfordiana. Species of Dicerandra are threatened or endangered and restricted to sand hill vegetation and a mosaic of scrub habitats.  Some species (D. cornutissima, D. thinicola, D. immaculata, D. frutescens, D. christmanii, and D. radfordiana) are restricted to only one or two sites in peninsular Florida and Georgia. Using locality and specimen data from iDigBio and other sources, we have applied ecological niche modeling to investigate shifts in abiotic niche space among species. Such shifts may have served as isolating mechanisms associated with speciation. These results will be used to reconstruct ancestral niche spaces when sea levels and climate were markedly different. We will make inferences on the possible ecological shifts and niche diversifications associated with speciation that have occurred during the evolution of the genus. 

Dicerandra frutescens Shinners, herbarium specimen USF142271 from the USF Herbarium, and available via the iDigBio portal.