Eupatorium vaseyi T.C. Porter. Phen: Jul-Oct. Hab: Moist to dry woodlands and openings, fire-maintained woodlands over mafic rocks (such as diabase). Dist: Various interpretations of this taxon have led to confusions and uncertainties regarding its distribution; Schilling (2011) shows records for e. TN and sc. KY and a recent discovery on Crowley's Ridge in AR (Witsell, pers. comm., 2017) represent the only confirmed distribution, but it should be sought elsewhere.
Origin/Endemic status: Endemic
Taxonomy Comments: This species is an apomictic species derived from E. petaloideum × sessilifolium (Schilling 2011). It has often been treated as a variety of E. album, but is better regarded as a species of hybrid origin.
Synonymy: = K3, K4, Tn, Va, Montgomery & Fairbrothers (1970), Schilling (2011b); = Eupatorium sessilifolium L. var. vaseyi (Porter) Fernald & Griscom – K1, RAB, WV; < Eupatorium album L. var. monardifolium Fernald – F, in part; < Eupatorium album L. var. vaseyi (Porter) Cronquist – C, FNA21, SE1, W, Cronquist (1985), (also see E. godfreyanum); < Eupatorium godfreyanum Cronquist – Pa; < Eupatorium vaseyi Porter – G