This southeastern taxon occurs largely on the Coastal Plain. It has been reported from Ky. by RAB, Bryan (1977) and others, but no coll. has been located. It is verified in Tenn., and should be looked for across w. Ky. in thin woods or edges with more seasonal water-stresses than the old fields and pastures of typical anceps (Ch, FNA 25, W). Ssp. rhizomatum is sometimes considered a distinct species (Hitchcock & Chase 1950). It differs from typical anceps in its longer rhizome segments (up to ca. 5-10 cm versus 1-5 cm); its more hairy sheath summits and blade bases (densely villous versus sparsely pilose to glabrous); its more contracted panicles; and its smaller spikelets (mostly 2.3-2.8 mm long versus 2.7-3.9 mm), which are less acuminate-falcate and often purplish (resembling rigidulum).