Dichanthium annulatum

HABIT Perennial; caespitose. Culms decumbent; 25–100 cm long. Ligule an eciliate membrane. Leaf-blades 3–30 cm long; 2–7 mm wide.

INFLORESCENCE Inflorescence composed of racemes. Peduncle glabrous.

Racemes (1–)2–15; digitate; 3–7 cm long. Rhachis fragile at the nodes; subterete; ciliate on margins. Rhachis internodes filiform. Raceme-bases filiform; glabrous.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; without a translucent median line; ciliate.

STERILE SPIKELETS Basal sterile spikelets absent, or well-developed; 0–12 in number (lower raceme); 0–12 in upper raceme; barren, or male; smaller than fertile. Basal sterile spikelet lemmas awnless.

Companion sterile spikelets well-developed; containing empty lemmas, or male; oblong; as long as fertile; separately deciduous. Companion sterile spikelet lemmas enclosed by glumes; muticous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; 2–6 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 oblong; 1 length of spikelet; cartilaginous; without keels. Lower glume surface concave; pubescent to villous; hairy below; with tubercle-based hairs (on margins & fringe); without hair tufts, or with a transverse fringe of hair. Lower glume margins ciliate. Lower glume apex obtuse, or acute. Upper glume lanceolate; 1-keeled; 3 -veined. Upper glume margins ciliolate.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline; 0 -veined; without midvein; without lateral veins. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 8–25 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION Africa: north, Macaronesia, west tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: western Asia, Arabia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, and north-central. North America: south-central USA and Mexico. South America: Mesoamericana, Caribbean, northern South America, and southern South America.

NOTES Andropogoneae. FTEA.

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