Bothriochloa wrightii

HABIT Perennial. Culms 50–100 cm long. Culm-nodes bearded. Lateral branches lacking. Ligule a ciliolate membrane. Leaf-blades 15–20 cm long; 3–5 mm wide. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–7; digitate; 3–6 cm long. Rhachis fragile at the nodes; flattened; ciliate on margins. Rhachis hairs 0.5–1.5 mm long. Rhachis internodes linear. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; with a translucent median line (also present in internodes); ciliate; with 0.5–1.5 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets well-developed; lanceolate; 6 mm long; as long as fertile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 6 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent; base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; cartilaginous; without keels; keel-less except near apex. Lower glume surface convex; without pits, or pitted. Lower glume margins ciliate. Upper glume lanceolate; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma linear; hyaline; without keel. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 10–15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION North America: south-central USA and Mexico.

NOTES Andropogoneae. Man US Gr 1994.

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