Echinochloa obtusiflora

HABIT Annual; caespitose; clumped loosely. Culms geniculately ascending; 15–45 cm long; 2 -noded. Culm-internodes terete; smooth; distally glabrous. Lateral branches sparse. Leaf-sheaths tight; striately veined; smooth; glabrous on surface. Ligule a fringe of hairs. Leaf-blades 5–10 cm long; 2–3 mm wide. Leaf-blade venation with 19 secondary veins. Leaf-blade surface glabrous. Leaf-blade margins scabrous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 2–5; borne along a central axis; unilateral; 1–2.5 cm long. Central inflorescence axis 3–15 cm long. Rhachis angular; 0.75 mm wide; scabrous on margins. Spikelet packing regular; 4 -rowed.

Spikelets in pairs. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; compressed slightly; obtuse; 2.2–3.4 mm long; falling entire. Spikelet callus oblong; incorporating lowest rhachilla internode with adnate lower glume; 0.5 mm long.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; clasping; 0.3–0.4 length of spikelet; membranous, or chartaceous; without keels; 5 -veined. Lower glume surface asperulous; rough above. Lower glume apex obtuse. Upper glume ovate; chartaceous; without keels; 5 -veined. Upper glume apex obtuse.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; chartaceous; 5 -veined; obtuse. Fertile lemma elliptic; 2.2–3.4 mm long; indurate; pallid; shiny; without keel. Lemma surface striate. Lemma margins involute. Lemma apex apiculate. Palea reflexed at apex; indurate.

FLOWER Anthers 3; 2 mm long.

DISTRIBUTION Africa: west tropical, west-central tropical, and northeast tropical.

NOTES Paniceae. FTA 1998.

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