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.

Nassella cernua

HABIT Perennial; caespitose; clumped densely. Culms erect; 60–90 cm long. Leaf-sheaths glabrous on surface. Ligule an eciliate membrane; 2 mm long. Leaf-blades flat, or involute; 1.2–2.4 mm wide; glaucous. Leaf-blade surface pilose; hairy adaxially, or on both sides.

INFLORESCENCE Inflorescence a panicle; exserted, or embraced at base by subtending leaf.

Panicle open; linear; 30–50 cm long. Primary panicle branches ascending, or spreading. Panicle branches flexuous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 12–19 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 2 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume linear, or lanceolate; 12–19 mm long; 1.1–1.7 length of upper glume; membranous; without keels; 3 -veined. Lower glume apex acuminate. Upper glume linear, or lanceolate; 11 mm long; 1.1–2 length of adjacent fertile lemma; membranous; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma elliptic; subterete; 5–10 mm long; chartaceous; without keel. Lemma surface papillose; pilose; hairy below. Lemma margins convolute; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn bigeniculate; 60–110 mm long overall; with twisted column. Column of lemma awn glabrous, or hispidulous. Palea ovate; 1–1.5 mm long; 0 -veined; without keels. Palea apex obtuse.

FLOWER Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; trigonous; 4 mm long; light brown. Hilum linear.

DISTRIBUTION Pacific: north-central. North America: southwest USA and Mexico.

NOTES Stipeae. Wagner 1993.

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