Muhlenbergia porteri

HABIT Perennial. Rootstock evident. Culms decumbent; slender; 30–100 cm long; wiry. Culm-internodes 1.5–6 cm long. Culm-nodes pubescent. Leaf-sheaths mostly shorter than adjacent culm internode. Ligule an eciliate membrane; 1–2(–2.5) mm long; lacerate. Leaf-blades flat, or involute; 2–5 cm long; 0.5–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate, or globose; effuse; 4–10 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; 5–20 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 3–4 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet, or reaching apex of florets; similar to fertile lemma in texture. Lower glume lanceolate; 2–3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 2–3 mm long; 0.66–1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 3–4 mm long; membranous; keeled; 3 -veined. Lemma surface puberulous; hairy between veins. Lemma apex acute; awned; 1 -awned. Principal lemma awn flexuous; 5–10(–13) mm long overall. Palea 1 length of lemma; 2 -veined. Palea apex acuminate.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.7–2 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform.

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

NOTES Eragrostideae. Gould.

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