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.

Aristida tuitensis

HABIT Perennial; caespitose. Culms erect; 1–2 mm diam.; 9–15 -noded. Culm-internodes terete; 2–12 cm long; distally glabrous. Culm-nodes glabrous. Lateral branches ample. Leaf-sheaths 3–9 cm long; longer than adjacent culm internode; indistinctly veined; glabrous on surface. Ligule a fringe of hairs; 0.2–0.3 mm long. Leaf-blades straight, or flexuous; flat; 10–50 cm long; 2–4 mm wide. Leaf-blade surface scaberulous; rough adaxially. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle. Peduncle 11–30 cm long; smooth, or scaberulous above.

Panicle open; ovate; effuse; 14–35 cm long; 12–20 cm wide; with spikelets clustered towards branch tips. Primary panicle branches spreading; 9–15 cm long. Panicle branches with prominent pulvini.

Spikelets in pairs. Fertile spikelets pedicelled. Pedicels 5–18 mm long.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 6–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.7–1 mm long; pubescent; obtuse.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 4–8 mm long; 0.7–0.9 length of upper glume; membranous; 3 -veined. Lower glume primary vein scabrous. Lower glume lateral veins obscure. Lower glume surface glabrous. Lower glume apex acute; mucronate, or awned; 1 -awned. Lower glume awn 0.5–2 mm long. Upper glume lanceolate; 6–7.5 mm long; membranous; 1 -veined. Upper glume primary vein smooth. Upper glume lateral veins absent. Upper glume apex obtuse; mucronate, or awned; 1 -awned. Upper glume awn 0.5–1 mm long.

FLORETS Fertile lemma linear; subterete; 4.5–6 mm long; 1–1.3 mm wide; coriaceous; without keel; 3 -veined. Lemma surface scaberulous; rough above. Lemma margins convolute; covering most of palea. Lemma apex awned; 1 -awned. Principal lemma awn geniculate; with twisted column. Column of lemma awn 6–10 mm long. Palea 0.5–0.7 mm long.

FLOWER Lodicules 2; 1–1.2 mm long. Anthers 3; 3–4 mm long.

DISTRIBUTION North America: Mexico.

NOTES Aristideae. Sanchez & Davila 2004.

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