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 megapotamica

HABIT Perennial; caespitose. Stolons present. Culms erect, or geniculately ascending; 15–20 cm long. Ligule a fringe of hairs. Leaf-blades 5–10 cm long; 1–2 mm wide; stiff.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–6; borne along a central axis; spreading; cuneate; unilateral; 1–1.5 cm long; bearing few fertile spikelets; bearing 3–10 fertile spikelets on each. Central inflorescence axis 1.5–2 cm long. Rhachis deciduous from axis; angular; terminating in a barren extension; extension a forked bristle. Spikelet packing broadside to rhachis.

Spikelets ascending; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets cuneate; laterally compressed; 11–12 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma; gaping. Lower glume lanceolate; 6 mm long; 0.6 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface hispid. Lower glume apex setaceously attenuate. Upper glume lanceolate; 10 mm long; 0.9 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface hispid. Upper glume apex dentate; 2 -fid; awned; 1 -awned. Upper glume awn 2 mm long.

FLORETS Fertile lemma ovate; 11–12 mm long; coriaceous; shiny; keeled; 3 -veined. Lemma apex dentate; 3 -fid; with central lobe bidentate; awned; 3 -awned. Principal lemma awn from a sinus; 5 mm long overall. Lateral lemma awns arising on inner edge of lobes; 4–5 mm long; subequal to principal. Palea apex with excurrent keel veins. Rhachilla extension glabrous. Apical sterile florets 2–3 in number; barren; in a clump; lanceolate; 4 mm long. Apical sterile lemmas lobed; 2 -fid; acuminate; awned; 3 -awned. Apical sterile lemma awns 20 mm long; 9–12 per spikelet in number.

FRUIT Caryopsis with adherent pericarp; obovoid; 2–2.5 mm long. Embryo 0.66 length of caryopsis.

DISTRIBUTION South America: western South America, Brazil, and southern South America.

NOTES Cynodonteae. Griffiths.

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