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.

Deschampsia laxa

HABIT Perennial. Culms 50–100 cm long. Leaf-sheaths longer than adjacent culm internode. Ligule an eciliate membrane; 3–7 mm long; lacerate. Leaf-blades conduplicate; 6–10 cm long; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; effuse; nodding; 15–20 cm long. Primary panicle branches 5–15 cm long. Panicle branches capillary.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 6–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; 1.5–2 mm long; pilose. Floret callus pilose. Floret callus hairs 1–2 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; similar to fertile lemma in texture; shiny. Lower glume linear; 6–9 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume linear; 6–9 mm long; 1.5 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 4–5 mm long; membranous; shiny; without keel; 5 -veined. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.33 way up back of lemma; straight; 4–6 mm long overall. Rhachilla extension pilose.

FLOWER Lodicules 2; membranous. Anthers 3; 1.5 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; fusiform; 2.5 mm long; dark brown. Hilum punctiform.

DISTRIBUTION South America: southern South America.

NOTES Aveneae. Fl Pat 1995.

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