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 macrantha

HABIT Perennial. Rhizomes elongated. Culms erect; 20–40 cm long. Culm-internodes terete; distally glabrous. Leaf-sheaths with 0.25 of their length closed; glabrous on surface. Ligule an eciliate membrane; 1–1.5 mm long; truncate. Leaf-blades involute; 1–2 mm wide; stiff. Leaf-blade surface pubescent; hairy adaxially.

INFLORESCENCE Dioecious. Inflorescence a panicle.

Panicle contracted; elliptic; 4–12 cm long. Primary panicle branches ascending. Panicle branches stiff; smooth.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–6 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth; pubescent. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 8–9 mm long; 0.75–0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume lanceolate; membranous; 1-keeled; 5 -veined. Upper glume apex acute.

FLORETS Fertile florets female. Fertile lemma ovate; elliptic in profile; 9–10 mm long; membranous; keeled; 5 -veined. Lemma midvein pubescent. Lemma surface pubescent; hairy on veins. Lemma margins pubescent. Lemma apex acute. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; 1.3 mm long; membranous. Anthers 3; 3.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

MALE Male inflorescence similar to female. Male spikelets similar to female but less developed.

CLEISTOGENES AND VIVIPARY Vivipary absent, or occurs.

DISTRIBUTION North America: western Canada, northwest USA, and southwest USA.

NOTES Poeae. Pl Pac NW 1996.

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