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 contracta

HABIT Perennial; caespitose; clumped loosely. Culms erect, or geniculately ascending; 30–90 cm long; 4 -noded. Culm-internodes smooth. Culm-nodes glabrous. Leaf-sheaths scaberulous. Ligule an eciliate membrane; 2–3 mm long; obtuse. Leaf-blades 4–17 cm long; 2–3.5 mm wide. Leaf-blade surface scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear, or lanceolate; equilateral, or nodding; 7–20 cm long. Primary panicle branches 2–4 -nate. Panicle axis with lower internodes 2–3 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1–1.5 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 2.5–3 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 0.2–0.7 mm long.

GLUMES Glumes persistent; similar; reaching apex of florets; firmer than fertile lemma; gaping. Lower glume lanceolate; 0.8 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume surface asperulous. Lower glume apex acute. Upper glume lanceolate; 2.5–3 mm long; 1 length of adjacent fertile lemma; membranous; with scarious margins; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume surface asperulous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 2.5–3 mm long; membranous; without keel; 5 -veined. Lemma lateral veins obscure. Lemma surface scaberulous. Lemma apex truncate; awned; 1 -awned. Principal lemma awn subapical; 0.5–1 mm long overall. Palea 1 length of lemma. Palea keels scaberulous; adorned above. Rhachilla extension 0.6 mm long; glabrous.

FLOWER Lodicules 2. Anthers 3; 0.3 mm long. Stigmas 2.

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

DISTRIBUTION Australasia: Australia.

NOTES Aveneae. Vickery 1994.

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