3. Bromus hordeaceus L. (soft chess, soft brome, bald brome, lopgrass)

Pl. 138 c, d; Map 558

B. mollis L.

Plants annual, forming tufts. Flowering stems 20–50(–70) cm long, erect or ascending, glabrous or more commonly hairy. Leaves 4–6(–10) per stem. Leaf sheaths loosely overlapping toward the base of the stem, hairy (the upper ones sometimes sparsely so), the tip strongly concave (V‑shaped), lacking a well‑defined ring of hairs on the outer surface and without auricles. Leaf blades 2–15 cm long, 2–6 mm wide, hairy, dull on the undersurface. Inflorescences short, dense panicles or less commonly racemes, with few to numerous spikelets, the branches appressed‑ascending at maturity, the stalks of the spikelets shorter than the spikelets. Spikelets 10–25 mm long, slightly compressed laterally at maturity, with 5–9 florets. Lower glume 5–7 mm long, narrowly elliptic‑lanceolate, 3(5)‑nerved, glabrous or evenly and conspicuously hairy. Upper glume 6–9 mm long, elliptic‑lanceolate, 7‑ or 9‑nerved, glabrous or evenly and conspicuously hairy. Lemmas 7–11 mm long, elliptic to narrowly obovate, the distance (in lemmas toward the middle of the spikelet) from the midnerve to margin 1.5–2.2 mm at the widest point, rounded on the back, the margins not or only slightly inrolled at maturity, with a narrow or broad, whitened band, 7‑ or 9‑nerved, glabrous or evenly and conspicuously hairy, the apical teeth 0.5–1.5 mm long, the awn (1.5–)3.0–9.0 mm long, rarely absent, straight or nearly so. Paleas shorter than the lemmas. Anthers 0.3–1.5 mm long. Fruits 4–6 mm long, circular in cross‑section to somewhat flattened or slightly V‑shaped, the longitudinal groove narrow and shallow. 2n=28. Late May–June.

Introduced, uncommon and widely scattered in Missouri (native of Europe, sporadically but widely naturalized in the U.S. and Canada). Disturbed openings of mesic upland forests; also roadsides railroads, pastures, margins of crop fields, and open, disturbed areas.

Bromus hordeaceus consists of several poorly differentiated subspecies, of which four have become naturalized in North America. Two of these occur in Missouri.