GrassBase - The Online World Grass Flora

Descriptions

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

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

Poa atropurpurea

HABIT Perennial; caespitose; clumped loosely. Rhizomes elongated. Butt sheaths herbaceous. Culms erect; 30–40 cm long; with 0.4 of their length below uppermost node. Culm-internodes terete. Leaves basal and cauline. Ligule an eciliate membrane. Leaf-blades straight; conduplicate, or involute; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; oblong; 3–5 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

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

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume oblong; 1.5–2 mm long; 0.75 length of upper glume; membranous; purple; 1-keeled. Lower glume apex acute. Upper glume lanceolate; 1.5–2 mm long; 0.75 length of adjacent fertile lemma; membranous; purple; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; 2.5 mm long; membranous; purple; keeled; 5 -veined. Lemma lateral veins obscure. Lemma surface glabrous. Lemma apex acute. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION North America: southwest USA.

NOTES Poeae. Man US Gr 1997.

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