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.

Deyeuxia rigescens

HABIT Perennial; caespitose. Rhizomes short. Culms 10–30 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 0.5–1 mm long. Leaf-blades flat, or involute; 4–10 cm long; 1–3 mm wide. Leaf-blade surface smooth, or scaberulous.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth, or scaberulous above.

Panicle spiciform; linear; 4–10 cm long; 0.5–0.8 cm wide.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels glabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 0.2–0.3 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4–5 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 3.5–4.3 mm long; membranous; without keel. Lemma surface smooth, or scaberulous; rough above. Lemma apex entire, or dentate; 2 -fid; obtuse; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; straight; 2–3.5 mm long overall. Rhachilla extension 0.5–0.8 mm long; pilose.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform. Disseminule comprising a floret.

DISTRIBUTION South America: western South America and southern South America.

NOTES Aveneae. Tovar 1995.

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