GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Bouteloua curtipendula

HABIT Perennial; caespitose. Rhizomes short; scaly. Culms 50–80 cm long. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades 10–30 cm long; 2–7 mm wide. Leaf-blade margins tuberculate-ciliate; hairy at base.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; 35–80; borne along a central axis; deflexed; cuneate; unilateral; 1–3(–4) cm long; bearing few fertile spikelets; bearing 1–12 fertile spikelets on each. Central inflorescence axis 15–25 cm long; flattened. Rhachis deciduous from axis; angular; 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; 5.5–8 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; exceeding apex of florets, or reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 4–5 mm long; 0.66–0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 5.5–8 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume primary vein scabrous. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 5–7 mm long; coriaceous; keeled; 3 -veined. Lemma surface smooth, or asperulous; rough on veins. Lemma apex dentate; 3 -fid; mucronate; 3 -awned (mucros). Rhachilla extension glabrous. Apical sterile florets 1 in number; barren; oblong; 0.5–0.75 mm long. Apical sterile lemmas lobed; 2 -fid; acute; awned; 3 -awned. Apical sterile lemma awns 3–7 mm long.

FRUIT Caryopsis with adherent pericarp; ellipsoid. Embryo 0.66 length of caryopsis.

DISTRIBUTION North America: western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, western South America, and southern South America.

NOTES Cynodonteae. Gould.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.