Thalictrum cooleyi H.E. Ahles. Section: Leucocoma. Phen: Late Jun-early Jul; Aug-Oct. Hab: Ecotones between calcareous savannas and adjacent swamp forests, shallowly underlain by coquina limestone ("marl"), generally within a few meters of both Taxodium ascendens and Liriodendron tulipifera. Dist: The species is endemic to two small areas, centered around Maple Hill (Pender and Onslow counties, NC) and Old Dock (Columbus and Brunswick counties, NC), with a small disjunct population in Panhandle FL (Walton County), and a small number of ambiguous populations in sw. GA (Dougherty and Worth counties); the GA populations are assigned here for now but may well represent a new taxon.
ID notes:The leaflets of basal leaves (winter rosettes) are much broader, resembling the leaflets of other Thalictrum species in length/width ratio. Leaves produced from May on have the very narrow leaves typical of the species.
Origin/Endemic status: Endemic
Taxonomy Comments: Park (1992) found that T. cooleyi has the highest chromosome number known in the genus, 2n = 210, a ploidy level of 30× compared to the base chromosome level of 7 in Thalictrum.
Other Comments: It is associated with a number of other narrow endemic species.
Synonymy: = Fl2, FNA3, GW2, K1, K3, K4, RAB, WH3, Park (1992)