Poa howellii

HABIT Annual; caespitose. Culms erect; 40–80 cm long. Lateral branches lacking. Leaf-sheaths tubular for much of their length; with 0.5 of their length closed; keeled; scaberulous. Ligule an eciliate membrane; 1–5 mm long; pubescent on abaxial surface; erose; truncate. Leaf-blades flat, or conduplicate; 5–10 cm long; 2–5 mm wide. Leaf-blade surface scabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 20–25 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; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2 mm long; 0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 2.5 mm long; 0.8 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

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

FLOWER Lodicules 2; membranous. Anthers 3; 0.7 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.