Poa wheeleri

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated. Butt sheaths herbaceous; green. Culms erect; 40–70 cm long. Culm-internodes terete. Leaf-sheaths tubular for much of their length; smooth, or scaberulous; glabrous on surface. Ligule an eciliate membrane; 0.5–2 mm long; scaberulous on abaxial surface; erose, or lacerate; obtuse, or acute. Collar glabrous. Leaf-blades flat; angular in section; 5–10 cm long; 3–5 mm wide. Leaf-blade surface scaberulous; glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 5–15 cm long; with spikelets clustered towards branch tips. Primary panicle branches spreading, or reflexed.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 6–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 2.6–3.5 mm long; 0.75 length of upper glume; membranous; 1-keeled. Lower glume apex acute. Upper glume lanceolate; 3–4.2 mm long; 0.66–0.8 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 4.5–5 mm long; membranous; keeled; 5 -veined. Lemma midvein scaberulous. Lemma lateral veins prominent. Lemma surface scaberulous; rough on veins; glabrous, or puberulous; hairy between veins. Lemma apex acute. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; 0.8 mm long; membranous. Anthers 3; 2.5–3 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: northwest USA and southwest USA.

NOTES Poeae. Fl Pac NW 1997.

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