GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Muhlenbergia pauciflora

HABIT Perennial; caespitose. Rootstock evident. Culms decumbent; 20–70 cm long; wiry; without nodal roots, or rooting from lower nodes. Lateral branches ample; arising from lower culm. Leaf-sheaths mostly shorter than adjacent culm internode; without keel. Leaf-sheath auricles erect; 1.5–3 mm long. Ligule an eciliate membrane; 0.5–1 mm long. Leaf-blades filiform; flat, or involute; 4–12 cm long; 0.5–1 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear, or lanceolate; continuous, or interrupted; 5–12 cm long; 0.4–1(–1.5) cm wide. Primary panicle branches appressed; 3–6 cm long; bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels linear; 0.2–1.5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 3–4.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 1.5–3.5 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 1.5–3.5 mm long; 0.5–0.75 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 3–4.5 mm long; membranous; keeled; 3 -veined. Lemma surface smooth to scabrous. Lemma apex acute; awned; 1 -awned. Principal lemma awn straight, or flexuous; (5–)7–25 mm long overall. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3.

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.