Tridens flavus

HABIT Perennial; caespitose. Rhizomes short; knotty. Culms 60–180 cm long. Leaf-sheaths keeled. Ligule a fringe of hairs. Collar pubescent. Leaf-blades 10–50 cm long; 3–10 mm wide. Leaf-blade surface glabrous, or hispid. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 15–35 cm long. Primary panicle branches ascending, or drooping; 10–25 cm long. Panicle branches straight, or flexuous; viscid; pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 4–8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 5–9 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; shiny. Lower glume ovate; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse, or acute; mucronate. Upper glume ovate; 0.75 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex obtuse, or acute; mucronate.

FLORETS Fertile lemma elliptic; 3–5 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 dentate; 2 -fid; mucronate. Palea bowed outwards; 0.9 length of lemma. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp; oblong; dorsally compressed; concavo-convex; dark brown. Embryo 0.4 length of caryopsis; not projecting.

DISTRIBUTION North America: north-central USA, northeast USA, south-central USA, and southeast USA.

NOTES Eragrostideae. Gould.

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