Tridentopsis eragrostoides

HABIT Perennial; caespitose. Culms erect; 50–100 cm long. Ligule an eciliate membrane; 1.2–3 mm long. Leaf-blades 1.5–5 mm wide. Leaf-blade surface scabrous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; 10–30 cm long. Primary panicle branches spreading, or drooping; simple, or moderately divided; 6–12 cm long.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 1.5–2 mm long.

FERTILE SPIKELETS Spikelets comprising 5–12 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 3–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 1.7–2.7 mm long; 0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate; mucronate. Upper glume lanceolate; 2–3 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma elliptic; 2–3.2 mm long; chartaceous; without keel; 3 -veined. Lemma midvein pubescent; hairy below. Lemma lateral veins close to margins; excurrent. Lemma margins pubescent; hairy below. Lemma apex entire, or dentate; 2 -fid; emarginate, or obtuse; mucronate. Palea straight; 0.9 length of lemma. Palea keels smooth, or scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp; 1–1.3 mm long.

DISTRIBUTION North America: southwest USA, south-central USA, southeast USA, and Mexico. South America: Caribbean.

NOTES Eragrostideae. Gould.

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