1. Apera interrupta (L.) P. Beauv. (Italian windgrass)
Pl. 132 c,
d; Map 535
Agrostis interrupta L.
Flowering stems 10–45 cm long. Leaf sheaths with the ligule
1.5–4.0 mm long. Leaf blades 1–10 cm long, 1–4 mm wide, the margins usually
strongly inrolled. Inflorescences 5–18 cm long, relatively narrow, with
strongly ascending branches at maturity. Lower glume 1.7–2.2 mm long. Upper
glume 2.0–2.5 mm long. Lemma 1.6–2.2 mm long. Anthers 0.3–0.4 mm long. 2n=14,
28. May–July.
Introduced, uncommon, known thus far only from Boone County and St. Louis (native of Europe, Asia; introduced in the western U.S. sporadically east to Missouri and Massachusetts, also southern Canada). Railroads, lawns, and
disturbed, grassy areas.