Bouteloua repens

HABIT Perennial. Rootstock not evident, or evident. Culms erect, or geniculately ascending; 20–50 cm long. Ligule a ciliate membrane. Leaf-blades flat, or involute; 5–10 cm long; 1–5 mm wide. Leaf-blade surface glabrous, or hirsute; sparsely hairy. Leaf-blade margins tuberculate-ciliate; hairy all along, or at base.

INFLORESCENCE Inflorescence composed of racemes; exserted, or embraced at base by subtending leaf.

Racemes 3–12; borne along a central axis; unilateral; 2.5 cm long; bearing 3–9(–20) fertile spikelets on each. Central inflorescence axis 10–15 cm long; tip subulate. Rhachis deciduous from axis; angular; terminating in a barren extension; extension subulate. Spikelet packing broadside to rhachis.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex and with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 4.5–8 mm long; falling entire; deciduous with accessory branch structures. Floret callus glabrous, or pilose.

GLUMES Glumes similar; shorter than spikelet, or reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 4–7 mm long; 0.9 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 4.5–7.5 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scaberulous. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 4.5–8 mm long; coriaceous; keeled; 3 -veined. Lemma apex entire, or dentate; 3 -fid; muticous, or awned; 3 -awned. Principal lemma awn 0–3 mm long overall. Lateral lemma awns arising on margin of lemma; 0–1 mm long; shorter than principal. Palea apex muticous, or with excurrent keel veins. Rhachilla extension glabrous. Apical sterile florets 1 in number; male; oblong; 5–8 mm long. Apical sterile lemmas lobed; 5 -fid; awned; 3 -awned. Apical sterile lemma awns unequal; 4–8(–10) mm long.

FLOWER Anthers 3; 3–4.5 mm long; yellow, or orange, or red, or purple.

FRUIT Caryopsis with adherent pericarp; oblong; 3–4 mm long. Embryo 0.8 length of caryopsis.

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

NOTES Cynodonteae. Gould.

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