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 arenicola

HABIT Perennial; caespitose; clumped densely. Culms geniculately ascending; 20–60 cm long. Culm-nodes pubescent. Leaves basal and cauline. Leaf-sheath auricles absent, or erect. Ligule an eciliate membrane; 2–7(–9) mm long. Leaf-blades 4–14 cm long; 1–2 mm wide; glaucous. Leaf-blade surface scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 12–25(–30) cm long; 5–15 cm wide. Primary panicle branches spreading. Panicle branches stiff.

Spikelets appressed, or ascending; solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.5–3.5 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; 1.5–2(–2.5) mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface scabrous. Lower glume apex acute, or acuminate; muticous, or awned. Upper glume lanceolate; 1.5–2(–2.5) mm long; 0.5–0.6 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface scabrous. Upper glume apex acute, or acuminate; muticous, or awned.

FLORETS Fertile lemma lanceolate; 2.5–3.5 mm long; membranous; keeled; 3 -veined. Lemma midvein pubescent; hairy below. Lemma surface scabrous; rough above. Lemma margins pubescent; hairy above. Lemma apex acute; awned; 1 -awned. Principal lemma awn 0.5–2.5(–3.5) mm long overall. Palea 1 length of lemma; 2 -veined. Palea apex with excurrent keel veins.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.7–1.9 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform.

DISTRIBUTION North America: northwest USA, north-central 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.