GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Deyeuxia longiseta

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms erect, or geniculately ascending; 20–80 cm long; 1.2–1.5 mm diam.; 2–3 -noded. Leaves mostly basal. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1–3 mm long. Leaf-blades involute; 15–30 cm long; 2–6 mm wide. Leaf-blade surface pilose; sparsely hairy; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 8–15 cm long; 2.5–4 cm wide. Primary panicle branches 4–8 -nate; 1–3 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4–5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 0.66–0.75 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 4–5 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 4–5 mm long; 1.1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled. Upper glume primary vein scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 3.5–4.5 mm long; membranous; without keel; 5 -veined. Lemma lateral veins extending close to apex. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.6 way up back of lemma; geniculate; 7–10 mm long overall; with a straight or slightly twisted column. Palea 0.75 length of lemma.

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

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

DISTRIBUTION Asia-temperate: eastern Asia.

NOTES Aveneae. Koyama 1994.

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