Poa leibergii

HABIT Perennial; caespitose; clumped densely. Culms 10–30 cm long. Culm-internodes smooth. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths tubular for much of their length; with 0.5–0.66 of their length closed; smooth. Ligule an eciliate membrane; 1–4 mm long; entire, or erose; obtuse. Leaf-blades curled; flat, or involute; 2–6 cm long; 1 mm wide. Leaf-blade margins scaberulous. Leaf-blade apex abruptly acute; hooded.

INFLORESCENCE Inflorescence a panicle; comprising 3–10 fertile spikelets.

Panicle open; pyramidal; dense, or loose; 2–8 cm long; bearing few spikelets. Primary panicle branches bearing 1–2 fertile spikelets on each lower branch. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 4–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus bearded.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2.5–3.5 mm long; 0.8 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 3–4.2 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 3–4.5 mm long; membranous; purple; keeled; 5 -veined. Lemma lateral veins distinct. Lemma surface smooth, or asperulous; pubescent; hairy on back, or on veins. Lemma apex acute. Palea 1 length of lemma. Palea keels scabrous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 2.8–3.2 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: Subarctic, western Canada, northwest USA, and southwest USA.

NOTES Poeae. Fl Pac NW 1994.

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