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 alamosana

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 15–40 cm long. Leaf-sheaths hispid. Ligule a fringe of hairs. Leaf-blades 1–3 mm wide. Leaf-blade surface hispid; hairy on both sides; with tubercle-based hairs.

INFLORESCENCE Inflorescence composed of racemes.

Racemes (3–)4–8; borne along a central axis; cuneate; unilateral; 1–1.5 cm long; bearing few fertile spikelets; bearing 3–8 fertile spikelets on each. Central inflorescence axis 3–10 cm long; tip subulate. Rhachis deciduous from axis; angular; ciliate on margins; 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; 6–9 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 6–9 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface pubescent; hairy on veins. Lower glume apex acuminate to setaceously attenuate. Upper glume lanceolate; 6–9 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume surface pubescent; hairy on veins. Upper glume apex acuminate to setaceously attenuate.

FLORETS Fertile lemma elliptic; 6–9 mm long; coriaceous; keeled; 3 -veined. Lemma apex dentate; 3 -fid; with central lobe bidentate; awned; 3 -awned. Principal lemma awn 1–3 mm long overall. Lateral lemma awns arising on margin of lemma; 1–3 mm long; subequal to principal. Palea apex awned. Rhachilla extension glabrous. Apical sterile florets 1 in number; male; lanceolate; 3–4 mm long. Apical sterile lemmas awned; 3 -awned. Apical sterile lemma awns equal; (8–)11–14 mm long.

FRUIT Caryopsis with adherent pericarp; obovoid; 4–4.5 mm long. Embryo 0.75 length of caryopsis.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Cynodonteae. Gould.

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