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 tenuissima

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 25–70 cm long. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths scaberulous; glabrous on surface. Leaf-sheath oral hairs lacking. Ligule an eciliate membrane; 1.5–4 mm long; obtuse. Leaf-blades aciculate; 7–40 cm long; 0.4–0.5 mm wide. Leaf-blade surface scaberulous; rough on both sides; glabrous. Leaf-blade apex acute.

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

Panicle open; linear; equilateral; 10–25 cm long; bearing few spikelets.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; laterally compressed; 5–10.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.2–0.4 mm long; pilose; obtuse. Floret callus hairs 0.25–0.33 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 5–10.5 mm long; 1.1–1.3 length of upper glume; hyaline; pallid, or purple; without keels; 3 -veined. Lower glume lateral veins obscure. Lower glume apex attenuate. Upper glume lanceolate; 5–10.5 mm long; 3–4 length of adjacent fertile lemma; hyaline; pallid, or purple; without keels; 3 -veined. Upper glume lateral veins obscure. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; laterally compressed; 1.8–3.6 mm long; coriaceous; without keel; 5 -veined. Lemma surface asperulous; rough above; glabrous. Lemma margins convolute; covering most of palea. Lemma apex surmounted by a ring of hairs; with this appendage 0.2–0.3 mm long; awned; 1 -awned. Principal lemma awn geniculate, or bigeniculate; 50–90 mm long overall; with a straight or slightly twisted column. Column of lemma awn glabrous. Palea 0.5–1 mm long; 0 -veined; without keels.

FLOWER Lodicules 2, or 3. Anthers 3; 1.2–1.5 mm long; anther tip penicillate. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; linear; 1.5–2 mm long; dark brown. Hilum linear; 0.5–0.66 length of caryopsis.

DISTRIBUTION Africa: south. Australasia: Australia and New Zealand. North America: south-central USA and Mexico. South America: southern South America.

NOTES Stipeae. Torres 1994.

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