Rostraria trachyantha

HABIT Annual; caespitose; clumped loosely. Culms erect; 20–70 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2–3 mm long. Leaf-blades 3–6 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle glabrous.

Panicle spiciform; linear, or oblong; interrupted; loose; 6–7 cm long. Panicle axis pilose. Panicle branches pilose.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3 fertile florets; with a barren rhachilla extension. Spikelets obovate; laterally compressed; 3–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture; shiny; gaping. Lower glume lanceolate; 0.7–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume oblong; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 3–4 mm long; membranous; keeled; 5 -veined. Lemma midvein ciliate. Lemma surface pubescent; with tubercle-based hairs. Lemma apex truncate; awned; 1 -awned. Principal lemma awn subapical; 1.5–2 mm long overall. Palea gaping.

FLOWER Lodicules 2; membranous. Anthers 3. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: western South America.

NOTES Aveneae. Domin 1995.

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