GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Bromus squarrosus

HABIT Annual. Culms erect, or geniculately ascending; 10–50 cm long. Culm-nodes purple. Leaf-sheaths pubescent. Ligule an eciliate membrane. Leaf-blades 3–15 cm long; 1–6 mm wide. Leaf-blade surface glabrous, or hirsute.

INFLORESCENCE Inflorescence a panicle, or composed of racemes.

Panicle open; ovate; secund; 4–18 cm long; 3–6 cm wide; bearing few spikelets. Primary panicle branches indistinct the panicle almost racemose.

Racemes 1; single; paucilateral.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 8–30 fertile florets; with diminished florets at the apex. Spikelets oblong, or ovate; laterally compressed; 15–50 mm long; 4–15 mm wide; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; dissimilar; shorter than spikelet. Lower glume ovate; 5–8 mm long; 0.75 length of upper glume; membranous; without keels; 5–7 -veined. Lower glume surface glabrous, or hirsute. Lower glume apex acute. Upper glume elliptic; 6–9 mm long; 0.75 length of adjacent fertile lemma; membranous; without keels; 7–9 -veined. Upper glume surface glabrous, or pubescent. Upper glume apex acute.

FLORETS Fertile lemma trullate; widest at 0.5 of its length from base; 8–11 mm long; 5–9 mm wide; chartaceous; without keel; 7–11 -veined. Lemma surface glabrous, or hirsute. Lemma apex entire; emarginate, or acute; awned; 1 -awned. Principal lemma awn subapical; spreading, or reflexed; 4–11 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.75–2 mm long. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; 4.5–6.5 mm long; hairy at apex; apex fleshy. Hilum linear.

DISTRIBUTION Europe: central, southwestern, southeastern, and eastern. Africa: north and Macaronesia. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, China, and Mongolia. Australasia: Australia. North America: western Canada, north-central USA, and northeast USA.

NOTES Bromeae. Acedo 1996.

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