GrassBase - The Online World Grass Flora


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

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

Bouteloua radicosa

HABIT Perennial. Rhizomes elongated; scaly. Culms erect; 40–80 cm long. Ligule a fringe of hairs; 1 mm long. Leaf-blades 2–3 mm wide. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–12; borne along a central axis; unilateral; 1–3 cm long; bearing 3–10 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. Spikelets cuneate; laterally compressed; 7–12 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma; gaping. Lower glume lanceolate; 4 mm long; 0.7–0.8 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 5–6 mm long; 0.75–1.1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 4.5–8 mm long; coriaceous; keeled; 3 -veined. Lemma apex dentate; 3 -fid; awned; 3 -awned. Principal lemma awn 2–3 mm long overall. Lateral lemma awns arising on margin of lemma; 1 mm long; shorter than principal. Rhachilla extension glabrous. Apical sterile florets 1 in number; male; oblong; 5–8 mm long. Apical sterile lemmas lobed; 3 -fid; awned; 3 -awned. Apical sterile lemma awns unequal; 6–8 mm long.

FRUIT Caryopsis with adherent pericarp; 4–5 mm long. Embryo 0.8 length of caryopsis.

DISTRIBUTION North America: southwest USA, south-central USA, and Mexico.

NOTES Cynodonteae. Gould.

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