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 ternipes

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 50–150 cm long; 1.5–4 mm diam.; with 0.4–0.5 of their length below uppermost node. Culm-internodes solid; distally glabrous. Culm-nodes glabrous. Lateral branches lacking. Leaf-sheaths glabrous on surface. Ligule a fringe of hairs; 0.2 mm long. Leaf-blades flat, or involute; 25–50 cm long; 3–5 mm wide. Leaf-blade surface ribbed; scaberulous; glabrous; hairless except near base. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 25–50 cm long. Primary panicle branches 1 -nate. Panicle axis scabrous. Panicle branches scabrous.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets linear; subterete; 8–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 0.5–1 mm long; pilose; acute. Floret callus hairs 2–3 mm long.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma. Lower glume linear; 6.5–11.5 mm long; 0.8 length of upper glume; membranous; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute; awned; 1 -awned. Lower glume awn 1–2 mm long. Upper glume linear; 8–12 mm long; 0.5 length of adjacent fertile lemma; membranous; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute; awned; 1 -awned. Upper glume awn 1–2 mm long.

FLORETS Fertile lemma linear; subterete; 15–22.5 mm long; coriaceous; without keel; 3 -veined. Lemma margins convolute; covering most of palea. Lemma apex awned; 1 -awned, or 3 -awned. Principal lemma awn curved; 10–15 mm long overall; with 10–15 mm long limb; without a column. Lateral lemma awns 0–3 mm long; shorter than principal. Palea 0.5–1.3 mm long.

FLOWER Anthers 3; 2.7 mm long.

FRUIT Caryopsis with adherent pericarp; linear; 7–8.5 mm long.

DISTRIBUTION North America: southwest USA, south-central USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, and western South America.

NOTES Aristideae. Fl Costaric 1993.

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