Leymus ambiguus

HABIT Perennial; caespitose. Rhizomes absent, or short. Culms 30–90 cm long. Leaf-sheaths glabrous on surface, or pubescent. Leaf-sheath auricles absent, or falcate. Ligule a ciliolate membrane; 0.5–1.5 mm long. Leaf-blades involute; 5–20 cm long; 1–4 mm wide; coriaceous; stiff; glaucous. Leaf-blade surface ribbed; pubescent, or pilose; hairy abaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; erect; bilateral; 5–15 cm long. Spikelet packing broadside to rhachis. Rhachis internodes linear.

Spikelets in pairs. Fertile spikelets sessile; 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 2–4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 9–15 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes collateral; persistent; similar. Lower glume subulate; 3–15 mm long; coriaceous; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or pubescent. Upper glume subulate; 3–15 mm long; coriaceous; 1 -veined. Upper glume lateral veins absent. Upper glume surface glabrous, or pubescent.

FLORETS Fertile lemma lanceolate; 7–12 mm long; coriaceous; without keel; 5 -veined. Lemma surface puberulous. Lemma apex acute; muticous, or awned; 1 -awned. Principal lemma awn 0–5 mm long overall. Palea 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 4–7 mm long.

DISTRIBUTION North America: northwest USA and southwest USA.

NOTES Triticeae. Fl Pac NW 1994.

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