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 aleutensis

HABIT Perennial. Culms erect, or geniculately ascending; 40–130 cm long. Culm-internodes distally pubescent. Leaf-sheaths striately veined; pilose; with reflexed hairs. Ligule an eciliate membrane; 3.5–5 mm long; lacerate. Leaf-blades 13–35 cm long; 6–15 mm wide. Leaf-blade surface pilose; sparsely hairy, or moderately hairy; hairy on both sides.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 10–28 cm long; with spikelets clustered towards branch tips. Primary panicle branches ascending; bearing 2–3 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–6 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; compressed strongly; 22–40 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 9–13 mm long; 0.9 length of upper glume; membranous; 1-keeled; 3–5 -veined. Lower glume surface glabrous, or pubescent. Lower glume apex acute. Upper glume lanceolate; 10–15 mm long; 0.8 length of adjacent fertile lemma; membranous; 1-keeled; 7(–9) -veined. Upper glume surface glabrous, or pubescent. Upper glume apex acute.

FLORETS Fertile lemma oblong; 12–17 mm long; chartaceous; much thinner on margins; keeled; 9(–11) -veined. Lemma lateral veins prominent. Lemma surface pubescent. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; (3–)5–10 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 2.2–4.2 mm long. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Subarctic.

NOTES Bromeae. Pavlick 2004.

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