Tridens texanus

HABIT Perennial; caespitose. Culms erect; 20–75 cm long. Culm-internodes distally glabrous, or pilose. Culm-nodes glabrous. Leaf-sheaths without keel; glabrous on surface, or pilose; outer margin hairy. Ligule a ciliate membrane; 0.2–0.5 mm long. Collar pubescent. Leaf-blades 7–20 cm long; 1–5 mm wide. Leaf-blade surface hispid. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 5–16 cm long. Primary panicle branches drooping; sparsely divided. Panicle axis hispid. Panicle branches flexible; flexuous; hispid.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 6–12 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 6–13 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume oblong; 2–3 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse, or acute. Upper glume oblong; 2–3 mm long; 0.5–0.66 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex obtuse, or acute.

FLORETS Fertile lemma elliptic; 4–5 mm long; membranous; purple; without keel; 3 -veined. Lemma midvein pubescent; hairy below. Lemma lateral veins excurrent. Lemma margins pubescent; hairy below. Lemma apex dentate; 2 -fid; obtuse; mucronate. Palea bowed outwards. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp; oblong. Embryo not projecting.

DISTRIBUTION North America: south-central USA and Mexico.

NOTES Eragrostideae. Gr Texas 1993.

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