GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Nassella yaviensis

HABIT Perennial; caespitose. Butt sheaths pubescent. Basal innovations extravaginal. Culms erect; 70–80 cm long. Culm-internodes distally pubescent. Culm-nodes constricted; brown. Lateral branches lacking. Leaf-sheaths mostly shorter than adjacent culm internode; antrorsely scabrous; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule an eciliate membrane; 2 mm long. Collar pilose. Leaf-blades 2–4 mm wide. Leaf-blade surface glabrous, or hispid.

INFLORESCENCE Inflorescence a panicle.

Panicle open; effuse; nodding; 36–42 cm long. Primary panicle branches 12 cm long. Panicle axis puberulous. Panicle branches puberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; 9–10.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus elongated; 1.2–1.6 mm long; pubescent; pungent.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 9–10.5 mm long; 1 length of upper glume; membranous; purple; without keels; 3–4 -veined. Lower glume apex acuminate. Upper glume lanceolate; 9–10.5 mm long; membranous; purple; without keels; 3–4 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma linear; subterete; 7.5–9.5 mm long; chartaceous; without keel; 5 -veined. Lemma surface scaberulous; pilose; hairy below. Lemma margins convolute; covering most of palea. Lemma apex with a membranous corona and surmounted by a ring of hairs; with this appendage 0.6–0.9 mm long; awned; 1 -awned. Principal lemma awn bigeniculate; 45–59 mm long overall; with 25–31 mm long limb; with twisted column; deciduous. Middle segment of lemma awn ciliate. Column of lemma awn 10–16 mm long; ciliate; with 1.5–1.7 mm long hairs. Palea 0 -veined; without keels.

FLOWER Lodicules 2. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; linear; 5 mm long. Hilum linear; 1 length of caryopsis.

DISTRIBUTION South America: southern South America.

NOTES Stipeae. Torres 1997.

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