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 depauperata

HABIT Annual; caespitose. Culms 3–15 cm long. Culm-internodes distally hirsute. Lateral branches ample; arising from lower culm. Leaf-sheaths keeled; striately veined; smooth, or antrorsely scabrous. Leaf-sheath auricles erect. Ligule an eciliate membrane; 1.5–4.5 mm long; lacerate. Leaf-blades 1–2(–3) cm long; 0.5–1(–1.5) mm wide. Leaf-blade midrib conspicuous. Leaf-blade surface scabrous; glabrous, or hirsute. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; dense; 2–7 cm long; 0.2–0.5 cm wide. Primary panicle branches bearing 2–3 fertile spikelets on each lower branch; bearing spikelets almost to the base. Panicle axis bearing persistent branches, or deciduous branches.

Spikelets appressed; solitary. Fertile spikelets pedicelled; heteromorphic (shorter awned at base of branch). Pedicels linear.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2.5–3.5 mm long; breaking up at maturity, or falling entire; deciduous with accessory branch structures; disarticulating or below each fertile floret.

GLUMES Glumes persistent; dissimilar; reaching apex of florets; similar to fertile lemma in texture. Lower glume linear; 2.5–3.5 mm long; 1 length of upper glume; membranous; 1-keeled; 2 -veined. Lower glume surface scabrous; rough on veins. Lower glume apex dentate; 2 -fid; acute. Upper glume linear; 2.5–3.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface scabrous; rough on veins. Upper glume apex acuminate, or attenuate.

FLORETS Fertile lemma lanceolate; 2.5–3.5 mm long; membranous; keeled; 3 -veined. Lemma surface scabrous; rough above; pubescent; hairy below; hairy between veins. Lemma apex attenuate; muticous, or awned; 1 -awned. Principal lemma awn 0–10 mm long overall. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.5–0.8 mm long; yellow.

FRUIT Caryopsis with adherent pericarp; fusiform; 2 mm long.

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

NOTES Eragrostideae. Gould.

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