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 chihuahuana

HABIT Perennial. Culms slender; 40–50 cm long. Leaf-sheaths scaberulous; glabrous on surface. Ligule a fringe of hairs; 0.5 mm long. Leaf-blades involute; 6–17 cm long; 1–2 mm wide. Leaf-blade surface smooth, or scaberulous; glabrous, or pubescent; sparsely hairy; hairy adaxially. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–8; borne along a central axis; ascending; cuneate; unilateral; 0.8–1.6 cm long; bearing few fertile spikelets; bearing 2–5 fertile spikelets on each. Central inflorescence axis 3–6 cm long. Rhachis deciduous from axis; angular; pilose on surface; terminating in a barren extension; extension subulate. 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; 5–7 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 3–4 mm long; 0.5 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface glabrous, or pubescent; hairy at base. Lower glume apex acuminate. Upper glume lanceolate; 6–8 mm long; 1.3 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; 4–6 mm long; coriaceous; keeled; 3 -veined. Lemma surface puberulous; hairy on veins. Lemma apex dentate; 3 -fid; with central lobe bidentate; awned; 3 -awned. Principal lemma awn from a sinus; 2 mm long overall. Lateral lemma awns arising on inner edge of lobes; 1 mm long; shorter than principal. Apical sterile florets 1–2 in number; barren; in a clump; cuneate; 4–5 mm long. Apical sterile lemmas lobed; 4 -fid; awned; 3 -awned. Apical sterile lemma awns 7–9 mm long.

FLOWER Anthers 3; 2.5–3 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico.

NOTES Cynodonteae. Arrieta et al 2006.

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