10. Bromus secalinus L. (rye brome, cheat, chess)

Pl. 139 a–d; Map 565

Plants annual, forming tufts. Flowering stems 20–80(–120) cm long, erect or ascending, glabrous or more commonly hairy below the nodes. Leaves 3–10 per stem. Leaf sheaths loosely overlapping toward the base of the stem, glabrous or the lowermost ones hairy, the tip strongly concave (V‑shaped), lacking a well‑defined ring of hairs on the outer surface and without auricles. Leaf blades 4–35 cm long, 3–9 mm wide, glabrous or hairy, dull on the undersurface. Inflorescences open panicles with usually numerous spikelets, the branches spreading to ascending at maturity, the stalks of the spikelets longer than the spikelets. Spikelets 10–25 mm long, slightly compressed laterally at maturity, with 5–12 florets. Lower glume 4–6 mm long, narrowly elliptic‑lanceolate, 3‑ or 5‑nerved, glabrous but sometimes roughened along the midnerve. Upper glume 6–8 mm long, elliptic‑lanceolate, 5‑ or 7‑nerved, glabrous or hairy. Lemmas 6–9 mm long, elliptic‑obovate, the distance (in lemmas toward the middle of the spikelet) from the midnerve to margin 1.5–2.5 mm at the widest point, rounded on the back, the margins strongly inrolled around the palea and fruit at maturity, exposing the rachilla, lightly 7‑nerved, glabrous or less commonly hairy, with a narrow to relatively conspicuous, broad, whitened band (hidden at maturity), the apical teeth 0.7–1.5 mm long, awnless or the awn (0.5–)3–8 mm long, straight or somewhat curved, but not sharply twisted or bent. Paleas about as long as the lemmas. Anthers 1–2 mm long. Fruits 6–7 mm long, U‑shaped in cross‑section, the longitudinal groove broad and deep. 2n=14, 28. Late May–June.

Introduced, scattered nearly throughout Missouri (native of Europe, widely naturalized in the U.S. and Canada). Upland prairies, limestone and dolomite glades and disturbed banks of streams and rivers; also roadsides, railroads, pastures, fallow fields, and open, disturbed areas.

Robust, hairy individuals of B. secalinus might be confused with B. pubescens, which also can have lemmas with somewhat inrolled margins at maturity. In addition to its perennial habit, B. pubescens also has longer anthers (2.5–5.0 mm) and is generally more hairy.