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 mucronata

HABIT Perennial. Culms erect, or geniculately ascending; 60–100 cm long. Culm-nodes pubescent. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 0.5–1 mm long. Leaf-blades flat, or involute; 10–20 cm long; 1–3 mm wide. Leaf-blade surface pubescent; sparsely hairy; hairy on both sides.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; dense; nodding; 10–30 cm long. Primary panicle branches appressed, or ascending; 1–2 -nate.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 8–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 2 mm long; pubescent (tawny); acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume oblong; 1 length of upper glume; membranous; purple; without keels; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acuminate. Upper glume oblong; 25–40 mm long; membranous; purple; without keels; 5 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; subterete; 5–6 mm long; 1 mm wide; coriaceous; dark brown; without keel; 5 -veined. Lemma surface papillose; rough above; pubescent; hairy below. Lemma margins convolute; covering most of palea. Lemma apex with a short cylindrical neck and surmounted by a ring of hairs; with this appendage 0.5 mm long; awned; 1 -awned. Principal lemma awn bigeniculate; 35–50 mm long overall; with twisted column. Middle segment of lemma awn 8–9 mm long. Column of lemma awn 10 mm long; hispidulous. Palea 2 -veined; without keels.

FLOWER Lodicules 3. Anthers 3. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp. Hilum linear.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, northern South America, western South America, and southern South America.

NOTES Stipeae. N Amer Fl 1994.

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