Pycnanthemum flexuosum (Walter) Britton, Sterns, & Poggenburg. Phen: Jun-Sep; Sep-Oct. Hab: Moist to wet pine savannas, pine flatwoods, pocosin margins, mountain bogs, seepage areas on low elevation granite domes. Dist: Se. VA south to ne. FL, west to Panhandle FL and s. MS (Sorrie & LeBlond 2008) on the Coastal Plain; disjunct inland in bogs and rock outcrops of sw. NC with Coastal Plain affinities, and in sc. TN.
ID notes:Sometimes mistaken in vegetative condition for Eupatorium leucolepis, P. flexuosum can be distinguished by its square stem and aromatic odor.
Origin/Endemic status: Endemic
Taxonomy Comments: A diploid species (n = 18). Koellia hugeri Small, alleged to differ details of the calyx, was established for the plants of bogs of the Blue Ridge; it apparently is not morphologically segregated from other variation within the species (Grant & Epling 1943).
Synonymy: = C, F, Fl6, K1, K3, K4, RAB, Va, W, WH3, Chambers & Hamer (1992); = Pycnanthemum hyssopifolium Benth. – G, GW2, Grant & Epling (1943); > Koellia hugeri Small – S; > Koellia hyssopifolia (Benth.) Britton – S