Muhlenbergia scoparia

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with curly dead sheaths. Culms 60–100 cm long. Culm-internodes distally glabrous. Leaf-sheaths keeled; glabrous on surface. Ligule an eciliate membrane; 1 mm long. Leaf-blades conduplicate; 25–50 cm long; 2.5–3 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; equilateral, or nodding; 20–40 cm long; 4–6 cm wide. Primary panicle branches ascending.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–3 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 1.5–2 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; reaching apex of florets. Lower glume lanceolate; 0.8–1.2 mm long; 0.75 length of upper glume; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth, or asperulous; glabrous. Lower glume apex acute; mucronate. Upper glume lanceolate; 1–1.5 mm long; 1 length of adjacent fertile lemma; hyaline; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume surface smooth, or asperulous; glabrous. Upper glume apex acute; awned; 1 -awned. Upper glume awn 0.2–1 mm long.

FLORETS Fertile lemma linear; 1.5–2 mm long; membranous; without keel; 3 -veined. Lemma surface smooth, or scaberulous; pubescent; hairy at base. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn flexuous; 6–15 mm long overall. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.4 mm long.

FRUIT Caryopsis with adherent pericarp; fusiform.

DISTRIBUTION North America: Mexico.

NOTES Eragrostideae. Fl Nov Gal 1994.

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