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 sinuosa

HABIT Annual. Culms erect, or geniculately ascending; 12–50 cm long; 0.3–0.5 mm diam. Culm-internodes 1.7–2.7 cm long; scaberulous. Lateral branches ample; arising from lower culm. Leaf-sheaths 2.5–10 cm long; longer than adjacent culm internode; smooth, or scaberulous. Ligule an eciliate membrane; 1.5–3.1 mm long; erose, or lacerate; truncate, or obtuse. Leaf-blades flat, or involute; 2–8.5 cm long; 0.8–2 mm wide. Leaf-blade midrib prominent beneath. Leaf-blade surface scaberulous; rough abaxially; pubescent; hairy adaxially. Leaf-blade margins unthickened, or cartilaginous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 10–26 cm long; 2.8–8 cm wide. Primary panicle branches ascending, or spreading; 1–2 -nate; 2.6–7 cm long.

Spikelets deflexed; solitary. Fertile spikelets pedicelled. Pedicels filiform; 4–7 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.4–2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 0.7–1.2 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface pilose. Lower glume apex obtuse, or acute. Upper glume lanceolate; 0.7–1.2 mm long; 0.5 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume surface pilose. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma elliptic, or oblong; 1.4–2 mm long; membranous; without keel; 3 -veined. Lemma midvein pubescent; hairy below. Lemma margins pubescent; hairy below. Lemma apex obtuse, or acute; muticous. Palea 1.3–1.8 mm long; 2 -veined. Palea surface glabrous, or pubescent; hairy on back.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.6–1.2 mm long; green.

FRUIT Caryopsis with adherent pericarp; fusiform; 0.8–1.2 mm long.

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

NOTES Eragrostideae. Peterson 1994.

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