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 sitchensis

HABIT Perennial. Culms 50–150 cm long. Leaf-sheaths glabrous on surface, or pilose. Ligule an eciliate membrane; 2–8 mm long; erose. Leaf-blades 8–15 mm wide. Leaf-blade surface glabrous, or pilose; hairy adaxially, or on both sides.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 10–35 cm long; with spikelets clustered towards branch tips. Primary panicle branches appressed, or ascending, or spreading, or drooping; bearing 1–2 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–12 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; compressed strongly; 20–40 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; 8–10 mm long; 0.75 length of upper glume; membranous; 1-keeled; 3–5 -veined. Lower glume apex acute. Upper glume lanceolate; 10–13 mm long; 1.1–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 5–7 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 7–12 mm long; chartaceous; without keel; 5–7 -veined. Lemma surface glabrous, or puberulous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; 7–12 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1(–6) mm long; eventually exserted, or retained within floret. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex; apex fleshy. Hilum linear.

DISTRIBUTION Australasia: New Zealand. North America: Subarctic, western Canada, and northwest USA.

NOTES Bromeae. Fl Pac NW 1994.

ADDITIONAL CHARACTERS Veins a quarter to a third width of space between.

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