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 nutkaensis

HABIT Perennial; caespitose; clumped densely. Rhizomes short. Culms robust; 80–160 cm long. Lateral branches lacking. Ligule a ciliolate membrane; 6–8 mm long; truncate. Collar glabrous. Leaf-blades erect; flat, or involute; 6–12 mm wide; coriaceous. Leaf-blade surface scabrous; rough adaxially. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 12–20 cm long; 1.5–2 cm wide. Primary panicle branches ascending.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 4.5–6.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus bearded. Floret callus hairs 0.5 length of lemma.

GLUMES Glumes persistent; similar; reaching apex of florets; firmer than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 4.5–6.5 mm long; 1.1–1.4 length of adjacent fertile lemma; membranous; 1-keeled; 1–3 -veined. Upper glume primary vein scaberulous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 4–4.5 mm long; membranous; without keel; 5 -veined. Lemma apex dentate; 4 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; straight, or geniculate; 0.5–2 mm long overall; not or scarcely exserted from spikelet; with a straight or slightly twisted column. Palea 1 length of lemma. Rhachilla extension 1 mm long; 0.25 length of fertile floret; pubescent.

FLOWER Lodicules 2; 0.8 mm long. Anthers 3; 3 mm long. Stigmas 2.

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

DISTRIBUTION Asia-temperate: Soviet far east. North America: Subarctic, western Canada, northwest USA, and southwest USA.

NOTES Aveneae. Fl Pac NW 1994.

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