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 azorica

HABIT Annual; caespitose. Culms erect; 2.5–18 cm long. Lateral branches lacking. Leaf-sheaths pubescent. Ligule an eciliate membrane; 0.5–1.5 mm long; lacerate; obtuse. Leaf-blades 2–11 cm long; 1.5–3 mm wide. Leaf-blade surface pubescent; densely hairy; hairy on both sides.

INFLORESCENCE Inflorescence a panicle.

Panicle spiciform; oblong; 1.5–8 cm long; 0.3–0.9 cm wide. Panicle axis scaberulous. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–8 fertile florets; with diminished florets at the apex. Spikelets obovate; laterally compressed; 5.5–9 mm long; 2–5 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent; with 0.1–0.5 mm long hairs.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture; shiny; gaping. Lower glume elliptic; 3–6.5 mm long; 0.7 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume elliptic; 4–7 mm long; 0.8–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 5 -veined. Upper glume primary vein scabrous. Upper glume apex acute; muticous, or mucronate.

FLORETS Fertile lemma elliptic; 5–6 mm long; membranous; shiny; keeled; 5 -veined. Lemma surface smooth, or papillose; glabrous, or pubescent. Lemma hairs 0.5–0.75 mm long. Lemma apex emarginate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.66–0.8 way up back of lemma; curved, or geniculate; 2.25–4 mm long overall; with a straight or slightly twisted column. Palea gaping; 0.75–1 length of lemma. Palea keels scaberulous. Palea apex dentate; 2 -fid; awned; awns 0.31 mm long. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 0.9–1.6 mm long. Ovary glabrous.

DISTRIBUTION Africa: Macaronesia.

NOTES Aveneae. Henderson 2005.

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