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.

Rostraria cristata

HABIT Annual; culms solitary, or caespitose. Culms erect, or decumbent; 5–45 cm long. Leaves mostly basal. Ligule an eciliate membrane; 1 mm long. Leaf-blades flat; 2.5–15 cm long; 1.5–8 mm wide; flaccid. Leaf-blade surface glabrous, or pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear, or lanceolate; continuous, or interrupted; 1.5–10 cm long; 0.6–1.6 cm wide. Panicle branches scaberulous; glabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong.

FERTILE SPIKELETS Spikelets comprising 3–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 3–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; pubescent.

GLUMES Glumes persistent; similar; reaching apex of florets, or shorter than spikelet; similar to fertile lemma in texture; shiny; gaping. Lower glume lanceolate; 2–3 mm long; 0.7 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or puberulous. Lower glume apex acuminate. Upper glume elliptic; 3–4 mm long; 1 length of adjacent fertile lemma; membranous; with hyaline margins; without keels; 3 -veined. Upper glume surface glabrous, or puberulous. Upper glume apex acute.

FLORETS Fertile lemma oblong; oblong in profile; 3–4 mm long; membranous; much thinner on margins; shiny; keeled; 5 -veined. Lemma surface smooth, or tuberculate; glabrous, or pubescent. Lemma apex obtuse, or acute; mucronate, or awned; 1 -awned. Principal lemma awn apical, or subapical; 0–3 mm long overall. Palea gaping. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.3 mm long. Ovary glabrous.

DISTRIBUTION Europe: southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, northeast tropical, and south. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, Arabia, and eastern Asia. Asia-tropical: India. Australasia: Australia. North America: northwest USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Caribbean, western South America, Brazil, and southern South America.

NOTES Aveneae. FTA.

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