Muhlenbergia virescens

HABIT Perennial; caespitose. Rhizomes absent, or short. Butt sheaths persistent and investing base of culm; with curly dead sheaths. Culms erect; 30–80 cm long. Leaf-sheaths without keel. Ligule an eciliate membrane; 2–4 mm long. Leaf-blades flexuous; flat, or involute; 10–30 cm long; 1–3 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 5–10 cm long. Primary panicle branches appressed; 2–5 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–1 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 3.5–5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; dissimilar; exceeding apex of florets. Lower glume lanceolate; 2.5–3 mm long; 0.66–0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse, or acute. Upper glume lanceolate; 3.5–5 mm long; 1.1 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex erose, or dentate; 3 -fid; truncate.

FLORETS Fertile lemma linear; 3–4 mm long; membranous; without keel; 3 -veined. Lemma surface pilose; hairy all along. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 10–15 mm long overall. Palea 1 length of lemma; 2 -veined. Palea surface pilose; hairy on back.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 2–2.2 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform.

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

NOTES Eragrostideae. Fl Nov Gal 1994.

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