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 polygama

HABIT Perennial; caespitose; clumped densely. Culms erect; 90–100 cm long; 4 -noded. Leaf-sheaths scaberulous; pubescent. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades filiform; convolute; 40–45 cm long; 6–8 mm wide; flaccid. Leaf-blade midrib indistinct. Leaf-blade surface scabrous; rough adaxially; pilose; hairy abaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong; 20–25 cm long. Primary panicle branches spreading; whorled at most nodes.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 3–3.2 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent. Floret callus hairs 1–1.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. 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; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface asperulous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 3–3.2 mm long; membranous; without keel; 5 -veined. Lemma surface pubescent; hairy above and at base. Lemma apex dentate; 2 -fid; acuminate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 2.5–3 mm long overall; with twisted column. Palea 3 mm long; 1 length of lemma. Rhachilla extension 1 mm long; 0.66 length of fertile floret; pilose.

FLOWER Lodicules 2. Anthers 3; 1.5–2 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; lanceolate; 1.8–2 mm long. Hilum punctiform. Disseminule comprising a floret.

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

NOTES Aveneae. Turpe 1995.

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