Muhlenbergia fragilis

HABIT Annual; caespitose; clumped loosely. Culms geniculately ascending; 10–35 cm long. Culm-internodes distally hirsute. Lateral branches lacking, or ample; arising from lower culm. Leaf-sheath auricles erect. Ligule an eciliate membrane; 1.5–2.5 mm long; hyaline. Leaf-blades flat, or conduplicate; 2–5(–6) cm long; 1.5–2 mm wide. Leaf-blade midrib widened. Leaf-blade surface scabrous; glabrous, or hirsute. Leaf-blade margins cartilaginous.

INFLORESCENCE Inflorescence a panicle; deciduous as a whole.

Panicle open; oblong; effuse; 7–25 cm long; 0.66–0.75 of culm length.

Spikelets spreading; solitary. Fertile spikelets pedicelled. Pedicels filiform; 2.5–8 mm long; tip widened.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 0.9–1.3 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 0.6–0.9 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous. Lower glume apex obtuse, or acute. Upper glume lanceolate; 0.6–0.9 mm long; 0.66–0.75 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface glabrous. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma lanceolate; 0.9–1.2 mm long; membranous; without keel; 3 -veined. Lemma midvein eciliate, or pubescent; hairy below. Lemma margins eciliate, or pubescent; hairy below. Lemma apex acute; muticous. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.4–0.5 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 0.6–0.9 mm long; dark brown, or red.

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.