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 purpurascens

HABIT Perennial; caespitose; clumped densely. Rhizomes absent, or short. Butt sheaths persistent and investing base of culm; with fibrous dead sheaths. Culms 30–90 cm long. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth, or antrorsely scabrous; pubescent. Ligule an eciliate membrane; 2–4 mm long; pubescent on abaxial surface; erose; truncate. Collar pubescent. Leaf-blades erect; flat, or involute; 2–4 mm wide; coriaceous; stiff. Leaf-blade surface scabrous; rough adaxially; pubescent; hairy adaxially.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; 4–10 cm long; 1 cm wide. Primary panicle branches appressed; bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 5–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 1.5 mm long; 0.33 length of lemma.

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 surface scabrous. Lower glume apex acute. Upper glume lanceolate; 5–8 mm long; 1.1–1.2 length of adjacent fertile lemma; membranous; 1-keeled; 1–3 -veined. Upper glume surface scabrous. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 4–7 mm long; membranous; without keel; 5 -veined. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.2 way up back of lemma; geniculate; 6–10 mm long overall; clearly exserted from spikelet; with twisted column. Palea 1 length of lemma. Rhachilla extension pilose; with 1 mm long hairs.

FLOWER Lodicules 2; 0.6 mm long. Anthers 3; 2.5–2.8 mm long. Stigmas 2.

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

DISTRIBUTION Asia-temperate: Siberia, Soviet far east, and eastern Asia. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, and southwest USA.

NOTES Aveneae. Fl Pac NW 1994.

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