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.

Rostraria rohlfsii

HABIT Annual; caespitose; clumped loosely. Culms erect, or geniculately ascending; 15–30 cm long; 2–5 -noded. Leaf-sheaths pubescent. Ligule an eciliate membrane; 0.5–1 mm long. Leaf-blades 2–10 cm long; 1.5–3 mm wide; flaccid. Leaf-blade surface pubescent. Leaf-blade apex abruptly acute; hardened.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; linear, or lanceolate; 3–10 cm long; 0.6–1 cm wide. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; 0.5–1 mm long.

FERTILE SPIKELETS Spikelets comprising 2–4 fertile florets; with diminished florets at the apex. Spikelets oblong, or obovate; laterally compressed; 4–5.5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; dissimilar; reaching apex of florets; similar to fertile lemma in texture; gaping. Lower glume lanceolate; 3–3.5 mm long; 0.75 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent, or distinct. Lower glume surface pubescent. Lower glume apex acuminate. Upper glume elliptic; 4–5 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface glabrous. Upper glume apex acute.

FLORETS Fertile lemma oblong; 3–4 mm long; membranous; much thinner on margins; keeled; 3–5 -veined. Lemma midvein scabrous. Lemma surface asperulous; glabrous. Lemma apex acute; awned; 1 -awned. Principal lemma awn dorsal; arising 0.8 way up back of lemma; 1–3 mm long overall. Palea gaping; hyaline. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.5–0.7 mm long. Ovary glabrous.

DISTRIBUTION Africa: north and west tropical.

NOTES Aveneae. FTA 1993.

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