This is a midwestern species, generally found in rocky woodlands, and with almost no records from southeastern states (K). There are a few records from s. Ind. and s. Ohio, but only one record from Ky. and one possible record from Tenn. (R. Kral #84785 at UCHT, from Morgan Co.). The Ky., coll. is from BULL (APSC) and recently identified by Brock (2020): M. Medley [& R. Cassell] #18946; 20 May 1988; Brooks Quadrangle, S side of Mud Run and W of [West] Blue Lick Road, low flatwoods; Isoetes melanopoda and Stachys aspera have been found nearby. P. wolfii is easily confused with sylvestris but differs as follows (FNA 24): lower panicle branches fewer per node (mostly 1-3 versus 4-5); spikelets larger (4-6.5 mm versus 2-4.4 mm) and less dense; lemmas larger (3.5-4.5 mm versus 2.1-3.1 mm), and usually glabrous between the veins (versus usually with sparse soft puberulence).