Muhlenbergia orophila

HABIT Perennial; caespitose; clumped densely. Culms erect; 12–30 cm long. Culm-internodes smooth, or scaberulous. Leaves mostly basal. Leaf-sheaths longer than adjacent culm internode; without keel; glabrous on surface. Ligule an eciliate membrane; 0.3–0.5(–1) mm long; erose; truncate. Leaf-blades flat, or involute; 5–8 cm long; 1–1.5 mm wide. Leaf-blade surface smooth, or scaberulous. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 5–8 cm long; 2–3 cm wide. Primary panicle branches appressed, or ascending. Panicle branches capillary.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; flexuous; 4–6 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 3–3.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus sparsely hairy.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1–1.5 mm long; 0.5–0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or setaceously attenuate. Upper glume lanceolate; 2 mm long; 0.66 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or setaceously attenuate.

FLORETS Fertile lemma lanceolate; 3–3.5 mm long; membranous; without keel; 3 -veined. Lemma surface puberulous; hairy at base. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn from a sinus; 0.5–1 mm long overall. Palea 2 -veined.

FLOWER Lodicules 2; cuneate; fleshy. Anthers 3; 1.5 mm long; purple.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Eragrostideae. Fl Meso-Am 1995.

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