Bouteloua triaena

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 20–50 cm long. Ligule a ciliolate membrane. Leaf-blades 2–6 cm long; 1–3 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; 20–80; borne along a central axis; deflexed, or spreading; unilateral; 0.5–0.6 cm long; bearing 1 spikelet; bearing 1 fertile spikelets on each. Central inflorescence axis 8–15 cm long; tip subulate. Rhachis deciduous from axis; subterete; terminating in a barren extension; extension bristle-like. Spikelet packing broadside to rhachis.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 5–6 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet; similar to fertile lemma in texture; gaping. Lower glume lanceolate; 2–3 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 4–6 mm long; 0.66–0.75 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 6–8 mm long; membranous; yellow, or purple; keeled; 3 -veined. Lemma surface puberulous. Lemma apex entire; acute; muticous. Rhachilla extension glabrous. Apical sterile florets 1 in number; barren; rudimentary. Apical sterile lemmas awned; 3 -awned. Apical sterile lemma awns 10–15 mm long.

FLOWER Anthers 3; yellow, or orange.

FRUIT Caryopsis with adherent pericarp; ovoid; 3 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Cynodonteae. Gould.

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