Poa leptocoma

HABIT Perennial; culms solitary, or caespitose; clumped loosely. Butt sheaths herbaceous. Culms geniculately ascending, or decumbent; 20–100 cm long. Culm-internodes terete; smooth, or scaberulous. Leaf-sheaths with 0.25–0.5 of their length closed; smooth, or scaberulous; glabrous on surface. Ligule an eciliate membrane; 1.5–4 mm long; glabrous on abaxial surface; entire, or erose; truncate, or obtuse. Leaf-blades flat, or conduplicate; 8–15 cm long; 1–4 mm wide; light green. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; nodding; 7–10 cm long. Primary panicle branches spreading, or reflexed; 1–3 -nate. Panicle branches capillary; smooth.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–5 fertile florets; with diminished florets at the apex. Spikelets oblong, or ovate; laterally compressed; 4–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas; smooth. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume linear; 0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume surface asperulous; rough on veins. Lower glume apex acute. Upper glume lanceolate; membranous; 1-keeled; 1–3 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent, or obscure. Upper glume surface asperulous; rough on veins. Upper glume apex acute.

FLORETS Fertile lemma oblong; elliptic in profile; 3–4 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma midvein ciliate; hairy below. Lemma lateral veins with distinct primaries but obscure intermediates. Lemma surface pubescent; hairy on veins. Lemma margins ciliate; hairy below. Lemma apex acute. Palea 0.9 length of lemma. Palea keels scaberulous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.25–1 mm long; eventually exserted, or retained within floret.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-temperate: Siberia and Soviet far east. North America: Subarctic, western Canada, northwest USA, southwest USA, and south-central USA.

NOTES Poeae. Soreng 1992.

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