Coreopsis palustris Sorrie. Phen: Sep-Oct. Hab: Blackwater swamp forests, wet and very wet loamy pine savannas, tidal freshwater swamp forests, swamp edges, borrow pits. Dist: Se. NC south to ne. FL (records outside this area, so far as is known, all represent misidentifications).
Origin/Endemic status: Endemic
Taxonomy Comments: The validity of this taxon has been controversial, and its nomenclature also difficult; see Weakley et al. (2011). Smith (1976) includes it in C. gladiata, considering it merely a pubescent form. Cronquist (in SE) regards it as distinct at the species level, despite his serious over-lumping of all its close relatives into a single species with two varieties: C. gladiata var. gladiata (including C. falcata and C. gladiata), and var. linifolia (including C. oniscicarpa and C. linifolia).
Synonymy: = K4, Sorrie, LeBlond, & Weakley (2013); = Coreopsis helianthoides Beadle – RAB, S, SE1, Sherff & Alexander (1955), Smith (1976), misapplied (the type actually belonging to C. gladiata); < Coreopsis gladiata Walter – FNA21, GW2, K1, WH3