Echinochloa colona

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 10–100 cm long. Leaf-sheaths glabrous on surface. Ligule absent. Leaf-blades 5–30 cm long; 2–8 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes borne along a central axis; ascending (rarely), or appressed; unilateral; 0.5–3 cm long; simple. Central inflorescence axis 1–15 cm long. Rhachis angular. Spikelet packing crowded; regular; 4 -rowed.

Spikelets in pairs, or clustered at each node. Fertile spikelets sessile; 2–4 in the cluster; subequal.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate, or orbicular; dorsally compressed; gibbous; acute, or cuspidate; 1.5–3 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.3–0.4 length of spikelet; without keels; 3–5 -veined. Lower glume surface scabrous. Lower glume apex cuspidate. Upper glume ovate; membranous; without keels; 5 -veined. Upper glume surface pubescent. Upper glume apex cuspidate.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; pubescent; acute, or cuspidate. Fertile lemma ovate; gibbous; 2–3 mm long; indurate; much thinner above; shiny; without keel; 5 -veined. Lemma margins involute. Lemma apex acute; laterally pinched. Palea reflexed at apex; indurate.

FLOWER Anthers 3.

DISTRIBUTION Europe: southwestern and southeastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, middle Atlantic ocean, 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, northwestern, and north-central. North America: northwest USA, north-central USA, northeast USA, southwest USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. FTEA.

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