This species is restricted mostly to southern Indiana where it is usually found in hard, white, slightly acid, clay soil in fallow fields where it is often abundant and usually associated with Alopecurus carolinianus, Myosotis virginica, and Arabis virginica. Since all of my specimens are from fallow and cultivated fields, it seems that one would be justified in assuming that it is being introduced from the area to the south of us. In 1937 it was an abundant weed in an Iris farm near Bluffton, Wells County.
Much like no. 23 [Poa annua L.], but the culms usually erect or strongly ascending and the sheaths close; spikelets avg a little smaller, the first glume 1.5-2.1 mm, the second 1.7-2.4 mm; lemmas hairy on the keel and marginal veins, and also webbed at base, the intermediate veins obscure; lowest lemma 1.6-2.5 mm; anthers 0.1-0.2 mm. Open ground and fields; Del. to Io., s. to the Gulf, and occasionally introduced northward. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.