Muhlenbergia tenuifolia

HABIT Annual, or perennial; short-lived. Culms weak; 20–75 cm long. Lateral branches sparse. Ligule an eciliate membrane; 1.5–2.3 mm long. Leaf-blades flat, or involute; 5–10 cm long; 1–2 mm wide. Leaf-blade surface smooth, or scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear, or oblong; interrupted; 5–15 cm long. Primary panicle branches spreading; 2–5 cm long; bearing spikelets almost to the base.

Spikelets spreading; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 2–3.4 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate, or ovate; 1.3–1.8 mm long; 0.66–0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute; muticous, or awned; 1 -awned. Lower glume awn 0.5 mm long. Upper glume lanceolate, or ovate; 1.7–2.7 mm long; 0.75 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute; muticous, or awned; 1 -awned. Upper glume awn 0.5 mm long.

FLORETS Fertile lemma lanceolate; subterete; 2–3.4 mm long; coriaceous; without keel; 3 -veined. Lemma lateral veins obscure. Lemma surface scaberulous. Lemma apex acuminate; awned; 1 -awned. Principal lemma awn 13–20 mm long overall. Palea 1 length of lemma; 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 0.9–1.2 mm long; pallid.

FRUIT Caryopsis with adherent pericarp; fusiform; 1.5–2 mm long.

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

NOTES Eragrostideae. Fl Nov Gal 1994.

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