GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Poa cuspidata

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated. Culms erect; 30–50 cm long. Culm-internodes terete; smooth. Lateral branches lacking. Culm-sheaths glabrous. Leaves mostly basal. Leaf-sheaths smooth. Ligule an eciliate membrane; 1–3 mm long; obtuse. Leaf-blades 30–50 cm long; 2–3 mm wide. Leaf-blade surface smooth. Leaf-blade apex abruptly acute.

INFLORESCENCE Monoecious (gynomonoecious). Inflorescence a panicle.

Panicle open; pyramidal; dense, or loose; 7–12 cm long; with spikelets clustered towards branch tips. Primary panicle branches ascending, or spreading; distant; 2 -nate. Panicle branches flexuous; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–4 mm long.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 3–6 mm long; with hairs extending 6–8 mm beyond apex; breaking up at maturity; disarticulating below each fertile floret. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 4–5 mm long; membranous; 1-keeled; 1(–3) -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent, or obscure. Lower glume apex acute. Upper glume lanceolate; 2 mm long; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma elliptic; elliptic in profile; 4–6 mm long; membranous; of similar consistency above; of similar consistency on margins; keeled; 5 -veined. Lemma midvein scabrous; pubescent; hairy all along. Lemma lateral veins distinct; stopping well short of apex. Lemma surface scaberulous; pubescent; hairy on back. Lemma margins pubescent; hairy below. Lemma apex acute. Palea keels scaberulous, or scabrous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 1; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: northeast USA and southeast USA.

NOTES Poeae. Man Gr US 2000.

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