Tripogon spicatus

HABIT Perennial; caespitose. Culms erect; 10–30 cm long. Leaves mostly basal. Leaf-sheaths without keel; glabrous on surface. Leaf-sheath oral hairs ciliate. Ligule a ciliolate membrane; 0.1–0.2 mm long. Leaf-blades filiform; involute; 3–10 cm long; 1 mm wide. Leaf-blade surface glabrous, or pilose; sparsely hairy.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; unilateral; 4–10 cm long. Rhachis flattened. Spikelet packing broadside to rhachis; regular; 2 -rowed.

Spikelets appressed; solitary. Fertile spikelets sessile, or pedicelled. Pedicels reduced to a stump; 0–0.3 mm long.

FERTILE SPIKELETS Spikelets comprising 6–12 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 5–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1–1.6 mm long; 0.5–0.66 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute, or acuminate. Upper glume lanceolate; 2.5–2.7 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma ovate; 3 mm long; membranous; without keel; 3 -veined. Lemma lateral veins extending close to apex. Lemma apex dentate; 2 -fid; mucronate, or awned; 1 -awned. Principal lemma awn from a sinus; 0.2–0.5 mm long overall. Palea 1 length of lemma; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FRUIT Caryopsis with adherent pericarp; lanceolate; 1.5 mm long; dark brown. Embryo 0.25 length of caryopsis.

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

NOTES Eragrostideae. Gr Texas 1994.

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