Bromus sterilis

HABIT Annual; culms solitary, or caespitose. Culms erect, or geniculately ascending; 15–100 cm long; 3–5 -noded. Leaf-sheaths hispid. Ligule an eciliate membrane; 2–4 mm long; erose. Leaf-blades 5–20 cm long; 2–7 mm wide. Leaf-blade surface pilose.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; effuse; nodding; 5–25 cm long. Primary panicle branches drooping; simple; 2–10 cm long; bearing 1(–3) fertile spikelets on each lower branch. Panicle branches flexuous; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–10 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 20–35 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; dissimilar; shorter than spikelet; gaping. Lower glume linear; 5–15 mm long; 0.6–0.7 length of upper glume; chartaceous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 7.5–20 mm long; 0.7–0.9 length of adjacent fertile lemma; chartaceous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 8–25 mm long; chartaceous; much thinner on margins; without keel, or keeled; lightly keeled; 7 -veined. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; incised 0.1–0.2 of lemma length; awned; 1 -awned. Principal lemma awn subapical; 15–40 mm long overall; limb scabrous. Palea 0.8 length of lemma. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.5–2 mm long. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; linear; hairy at apex; apex fleshy. Hilum linear; 1 length of caryopsis.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north and Macaronesia. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, China, and eastern Asia. Australasia: Australia and New Zealand. Pacific: north-central. North America: western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, and southeast USA. South America: Caribbean and southern South America.

NOTES Bromeae. Acedo 1996.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.