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 orbignyana

HABIT Perennial; caespitose; clumped densely. Culms 40–80 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane. Leaf-blades filiform; involute; 15–30 cm long; 1 mm wide. Leaf-blade surface scaberulous. Leaf-blade apex pungent.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 10–20 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 5.5–6 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; purple; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 5.5–6 mm long; 1.1–1.4 length of adjacent fertile lemma; membranous; purple; 1-keeled. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4–5.5 mm long; membranous; without keel. Lemma apex erose; awned; 1 -awned. Principal lemma awn dorsal; arising 0.25 way up back of lemma; geniculate; 6 mm long overall; with twisted column. Rhachilla extension 0.33 length of fertile floret; pilose.

FLOWER Lodicules 2. Anthers 3; 2.5 mm long. 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. Pilger 1995.

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