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 arcuata

HABIT Perennial; caespitose. Culms erect; 15–40 cm long; 2–3 -noded. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades convolute; 5–10 cm long; 1 mm wide. Leaf-blade surface ribbed; pubescent.

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

Panicle open; linear; 10–20 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.4–10 mm long; glabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 13–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 2 mm long; pubescent; acute.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 13–15 mm long; 1.3 length of upper glume; membranous; purple; without keels; 3 -veined. Lower glume apex acuminate. Upper glume lanceolate; 10–12 mm long; membranous; purple; without keels; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; subterete; 8–9 mm long; coriaceous; without keel; 5 -veined. Lemma midvein pubescent; hairy below. Lemma surface pubescent; hairy above. Lemma margins convolute; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn geniculate, or bigeniculate; 50–70 mm long overall; with twisted column; deciduous. Column of lemma awn ciliate; with 2 mm long hairs. Palea 1.7–2 mm long; 0.5 length of lemma; 0 -veined; without keels.

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

FRUIT Caryopsis with adherent pericarp; fusiform. Hilum linear.

DISTRIBUTION South America: western South America and southern South America.

NOTES Stipeae. Matthei 1995.

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