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 media

HABIT Perennial; caespitose. Rootstock not evident, or evident. Culms erect; 80–200 cm long; 5–7 -noded. Culm-nodes purple. Lateral branches sparse; arising from upper culm. Leaf-sheaths glabrous on surface to hirsute. Ligule a fringe of hairs; 0.2–0.5 mm long. Leaf-blades 4–9 mm wide. Leaf-blade surface glabrous to hirsute.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 7–15; borne along a central axis; unilateral; 2–6 cm long; bearing 10–20 fertile spikelets on each. Central inflorescence axis 4–30 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; 4–6 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; shorter than spikelet; thinner than fertile lemma; gaping. Lower glume linear; 2.5–3 mm long; 0.6–0.7 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth to scabrous; glabrous to pubescent. Lower glume apex acute to setaceously attenuate. Upper glume lanceolate; 3.4–4.5 mm long; 0.7–0.8 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface smooth to scabrous; glabrous to pubescent. Upper glume apex acute, or acuminate.

FLORETS Fertile lemma ovate; 4–6 mm long; coriaceous; keeled; 3 -veined. Lemma apex dentate; 3 -fid; awned; 3 -awned. Principal lemma awn 0.5–1 mm long overall. Lateral lemma awns arising on margin of lemma; 0.5–1 mm long; subequal to principal. Rhachilla extension glabrous. Apical sterile florets 1 in number; barren; oblong. Apical sterile lemmas dentate; 3 -fid; awned; 3 -awned. Apical sterile lemma awns 3–8 mm long.

FLOWER Anthers orange, or red.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 2.2–2.5 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, western South America, Brazil, and southern South America.

NOTES Cynodonteae. Gould.

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