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.

Bothriochloa exaristata

HABIT Perennial; caespitose. Culms 7–130 cm long. Ligule an eciliate membrane; 1–2 mm long. Leaf-blades flat, or conduplicate; 5–15 cm long; 3–8 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; borne along a central axis; closely spaced; 1–4 cm long. Central inflorescence axis 9–15 cm long. Rhachis fragile at the nodes; flattened; plumose on margins. Rhachis hairs 5–6 mm long. Rhachis internodes linear. Rhachis internode tip transverse; cupuliform.

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); plumose; hairy above; with white hairs; with 5–6 mm long hairs.

STERILE SPIKELETS Companion sterile spikelets represented by single glumes; linear; 2–4 mm long; shorter than fertile; separately deciduous. Companion sterile spikelet glumes glabrous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or elliptic; dorsally compressed; acute; 3 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; 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 flat; pilose. Upper glume elliptic; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma linear; hyaline; without keel. Lemma apex entire; muticous, or awned; 1 -awned. Principal lemma awn apical; straight; 1–4 mm long overall; without a column. Palea absent or minute.

DISTRIBUTION North America: south-central USA and southeast USA. South America: western South America, Brazil, and southern South America.

NOTES Andropogoneae. Gould.

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