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.

Muhlenbergia racemosa

HABIT Perennial. Rhizomes elongated; scaly. Culms 25–60(–100) cm long. Culm-internodes smooth; distally glabrous. Lateral branches lacking, or sparse. Leaf-sheaths keeled; smooth, or scaberulous, or antrorsely scabrous. Ligule an eciliate membrane; 0.6–1.5 mm long; erose, or lacerate; truncate. Leaf-blades flat, or involute; 4–10(–16) cm long; 3–5(–7) mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear, or lanceolate; interrupted; 3–10(–17) cm long; 0.4–1(–1.8) cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.2–4.5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 1.5–3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex attenuate; awned; 1 -awned. Lower glume awn 3–4.5 mm long. Upper glume lanceolate; 1.5–3 mm long; 0.66 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex attenuate; awned; 1 -awned. Upper glume awn 3–4.5 mm long.

FLORETS Fertile lemma lanceolate; 2.2–4.5 mm long; membranous; keeled; 3 -veined. Lemma midvein eciliate. Lemma surface pubescent; hairy at base. Lemma margins eciliate. Lemma hairs 0.5–0.9 mm long. Lemma apex attenuate; muticous. Palea 0.9 length of lemma; 2 -veined. Palea surface pilose; hairy on back; hairy below.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.4–0.7 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.4–2.3 mm long.

DISTRIBUTION North America: western Canada, eastern Canada, northwest USA, north-central USA, northeast 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.