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 pilosa

HABIT Perennial; caespitose. Rhizomes absent. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect; 50–130 cm long. Culm-internodes smooth, or scaberulous. Culm-nodes pubescent. Leaf-sheaths 5–70 cm long; longer than adjacent culm internode; without keel; scaberulous; outer margin hairy. Ligule an eciliate membrane; 0.5–5 mm long; lacerate; truncate, or obtuse. Leaf-blades flat, or involute; 15–35 cm long; 1–3 mm wide. Leaf-blade surface scaberulous; rough on both sides; glabrous, or pilose; sparsely hairy; hairy adaxially. Leaf-blade margins ciliate (sparsely).

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; 20–45 cm long; 3–8 cm wide. Primary panicle branches ascending; 0.3–4.7 cm long. Panicle branches pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–7 mm long; glabrous, or puberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.4–3.7 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1.8–3.2 mm long; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface pilose. Lower glume apex acute. Upper glume lanceolate; 1.8–3.2 mm long; 0.8–0.9 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume surface pilose. Upper glume apex acuminate; mucronate.

FLORETS Fertile lemma lanceolate, or elliptic; 2.1–3.7 mm long; membranous; without keel; 3 -veined. Lemma surface pilose. Lemma hairs 1–1.6 mm long. Lemma apex entire, or dentate; 2 -fid; with lobes 0.1–0.2 mm long; acute, or acuminate; awned; 1 -awned. Principal lemma awn apical, or from a sinus; flexuous; 18–31 mm long overall. Palea oblong; 2–3.5 mm long; 2 -veined. Palea surface pilose; hairy on back. Palea apex acute, or acuminate.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.3–1.9 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.1–1.4 mm long; light brown.

DISTRIBUTION North America: Mexico.

NOTES Eragrostideae. Peterson 2002.

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