Dichanthium aristatum

HABIT Perennial. Culms decumbent; 20–100 cm long. Ligule an eciliate membrane. Leaf-blades 3–25 cm long; 2–5 mm wide.

INFLORESCENCE Inflorescence composed of racemes. Peduncle pubescent above.

Racemes 1–6; digitate; 2–8 cm long. Rhachis fragile at the nodes; subterete; ciliate on margins. Rhachis internodes filiform. Raceme-bases filiform; pubescent.

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 well-developed; 2–12 in number (lower raceme); 2–12 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 elliptic, or obovate; dorsally compressed; 2–5 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, or obovate; 1 length of spikelet; chartaceous; of similar consistency above, or much thinner above; without keels. Lower glume surface convex; pilose; hairy below; with simple hairs. Lower glume margins eciliate, or ciliate. Lower glume apex obtuse, or acute. Upper glume lanceolate; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret hyaline. Fertile lemma linear; hyaline; without keel; 1 -veined. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 10–20 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

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

NOTES Andropogoneae. FTEA.

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