Bromus richardsonii

HABIT Perennial. Butt sheaths pilose. Culms 50–145 cm long. Culm-internodes distally glabrous. Culm-nodes glabrous. Leaf-sheaths glabrous on surface. Leaf-sheath oral hairs lacking, or ciliate. Ligule an eciliate membrane; 0.4–2 mm long; obtuse. Leaf-blades 10–35 cm long; 3–12 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; nodding; 10–25 cm long. Primary panicle branches ascending, or spreading, or drooping. Panicle branches capillary.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 6–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15–40 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 7.5–12.5 mm long; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous. Upper glume lanceolate; 9–13.5 mm long; membranous; without keels; 3 -veined. Upper glume surface glabrous. Upper glume muticous, or mucronate.

FLORETS Fertile lemma oblong; 9–16 mm long; chartaceous; without keel; 5 -veined. Lemma surface glabrous, or pubescent. Lemma margins ciliate; hairy below. Lemma apex awned; 1 -awned. Principal lemma awn subapical; 2–5 mm long overall. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 1–2 mm long. Ovary with a fleshy appendage above style insertion; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; hairy at apex.

DISTRIBUTION North America: Subarctic, northwest USA, southwest USA, south-central USA, and Mexico.

NOTES Bromeae. Pavlick 2004.

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