1b. var. flavus
T. flavus f. cupreus (Jacq.) Fosberg
Inflorescences usually somewhat arched or drooping, the
branches somewhat arched or drooping, their bases thickened only on 1 side,
glabrous or with a tuft of very short hairs on the thickened side. Spikelets
with the stalks 1–5 mm long, mostly appressed to the inflorescence branches. 2n=40.
July–September.
Common throughout the state (eastern U.S. and adjacent Canada west to Illinois, Nebraska, and Texas). Upland prairies, glades, savannas,
openings of mesic to dry upland forests and bottomland forests, and margins of
streams; also roadsides, railroads, ditches, old fields, and open, disturbed
areas.
This taxon spreads quickly into disturbed areas and is quite
common along roadsides in the state.