Poa rhizomata

HABIT Perennial; caespitose. Rhizomes elongated. Culms 40–60 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths scaberulous; glabrous on surface. Ligule an eciliate membrane. Collar pubescent. Leaf-blades flexuous; involute; 10–20 cm long; 0.5–1 mm wide. Leaf-blade surface puberulous; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 5–8 cm long. Primary panicle branches 2 -nate; 2–3 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 6–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 3–5 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume ovate; 3–5 mm long; 0.75–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; 4–5 mm long; membranous; keeled; 5 -veined. Lemma midvein pubescent; hairy below. Lemma lateral veins distinct. Lemma surface scaberulous; rough on veins. Lemma apex acute. Palea 1 length of lemma. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: northwest USA and southwest USA.

NOTES Poeae. Man US Gr 1994.

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