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 effusa

HABIT Perennial; caespitose; clumped densely. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Culms erect; 40–100 cm long. Ligule an eciliate membrane; obtuse. Leaf-blades erect; involute; 20–30 cm long; 2–3 mm wide; stiff. Leaf-blade surface glabrous. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 10–20 cm long. Primary panicle branches 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; 3–4 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

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; 3–4 mm long; 1–1.3 length of adjacent fertile lemma; membranous; 1-keeled. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 3 mm long; membranous; without keel; 5 -veined. Lemma apex awned; 1 -awned. Principal lemma awn dorsal; arising 0.6 way up back of lemma; geniculate; 2–4 mm long overall; with twisted column. Rhachilla extension pubescent; hairy throughout.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

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

DISTRIBUTION South America: northern South America and western South America.

NOTES Aveneae. Pilger 1995.

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