Corn Brome

The name Bromus wolgensis has been applied to a variant with pubescent spikelets.

Annual. Culms erect or geniculately ascending, 20–60 cm tall, 3–4(–5)-noded. Leaf sheaths pubescent; leaf blades flat, up to 15 cm × 2–5 mm, pubescent; ligule ca. 1 mm. Panicle lax, (5–)20 × 4–6 cm, usually 1-sided; branches few, shorter than or equaling spikelets, each bearing 1 or 2 pendent spikelets. Spikelets ovate, upper part gradually narrowed, (15–)20–50 × 5–15 mm, florets (6–)10–25; rachilla ca. 2 mm, smooth or scabrid; glumes oblong to elliptic, margins membranous, glabrous, lower glume 5–7 mm, 5-veined, apex acuminate, upper glume 6–8 mm, 9-veined, apex obtuse; lemmas obovate, 8–11 × (2–)3–6 mm in side view, 9-veined, glabrous or pubescent, margins white-membranous and angled near halfway point, apex entire or shallowly 2-toothed, awned from sinus ca. 2 mm below apex; awn 7–12 mm, longer on upper lemmas than lower lemmas, base flattened, slightly twisted, divaricate at maturity; palea 1/3 length of lemma, keels stiffly ciliate. Anthers 1–1.5 mm. Fl. and fr. May–Jul. 2n = 14.

Gansu, Xinjiang [Kazakhstan, Mongolia, Russia; N Africa, SW Asia, Europe; introduced in America].

Field margins, grasslands, waste ground; 500–3000 m.

Bromus wolgensis Fischer ex J. Jacquin; Forasaccus squarrosus (Linnaeus) Bubani; Serrafalcus squarrosus (Linnaeus) Babington.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly closed, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence lax, widely spreading, branches drooping, pendulous, Inflorescence with 2-10 branches, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets lat erally compressed, Spikelets with 3-7 florets, Spikelets with 8-40 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes 4-7 nerved, Glumes 8-15 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 5-7 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awn 1-2 cm long, Lemma awned from tip, Lemma awn subapical or dorsal, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter tha n lemma, Palea 2 nerved or 2 keeled, Palea keels winged, scabrous, or ciliate, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear, Caryopsis hairy at apex.

Bromus squarrosus, the rough brome, is a brome grass native to Russia and Europe. The specific epithet squarrosus is Latin, meaning "with spreading tips". The grass has a diploid number of 14.