Poa lettermanii

HABIT Perennial; caespitose; clumped densely. Culms 20–90 cm long. Lateral branches lacking. Leaf-sheaths open for most of their length; with 0.1 of their length closed. Ligule an eciliate membrane; 2–3 mm long; erose; acute. Leaf-blades 1 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; oblong; 1–3 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

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

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 3 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 3 mm long; 1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 2.5–3 mm long; membranous; purple; keeled; 5 -veined. Lemma surface glabrous. Lemma apex acute. Palea 1 length of lemma. Palea keels scaberulous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: 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.