Tridens albescens

HABIT Perennial; caespitose. Rhizomes short; knotty. Culms erect; 30–90 cm long. Ligule a fringe of hairs; 0.2–0.5 mm long. Leaf-blades 1–4 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; lanceolate; 8–25 cm long; 0.6–1.5 cm wide. Primary panicle branches appressed; 2–6 cm long.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–10 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 4–10 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; 3–4 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate; mucronate. Upper glume lanceolate; 3–4 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma elliptic; 3–4 mm long; chartaceous; without keel; 3 -veined. Lemma midvein eciliate. Lemma lateral veins close to margins; excurrent. Lemma margins eciliate. Lemma apex dentate; 2 -fid; mucronate. Palea bowed outwards; 0.9 length of lemma. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: northwest USA, north-central USA, south-central USA, and Mexico.

NOTES Eragrostideae. Gould.

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