Echinochloa stagnina (Retz.) P. Beauv.

African material is now recognised as belonging to a separate species, Echinochloa scabra (Lam.) Roem. & Schult. It is characterised by its slightly longer, narrower spikelets.

Aquatic perennial, sometimes behaving as an annual or a biennial; culms spongy, 40-150 cm high, decumbent and rooting at the nodes. Leaf-blades 8-50 cm long, 6-10 mm wide; ligule a line of hairs; sheaths glabrous. Inflorescence narrowly lanceolate, rarely narrowly ovate, 7-20 cm long, typically ± open with the racemes secund and usually ascending; racemes simple, 2-6.5 cm long, coarsely spiculate. Spikelets ovate to broadly ovate or rounded, 3.5-5 mm long, pubescent to hispid, often from tubercles; lower lemma tapering to an awn up to 10 mm long; upper lemma 34 mm long.

Distribution: Pakistan (Sind); tropical Asia.

Fl. & Fr. Per.: October-November, sometimes extending to February.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems trailing, spreading or prostrate, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax , sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blade with prominently raised or widened midvein, Leaf blades mostly glabrous, Ligule present, Ligule a fringe of hairs, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflor escence branches more than 10 to numerous, Inflorescence branches 1-sided, Rachis angular, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets paired at rachis nodes, Spikelets all alike and fertille, Spikelets in paired units, 1 sessile, 1 pedicellate, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes equal to or longer than adjacent lemma, Glumes awned, awn 1-5 mm or longer, Glumes keeled or winged, Glume surface hairy, villous or pilose, Glumes 4-7 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma becoming indurate, enclosing palea and caryopsis, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma margins inrolled, tightly covering palea and caryopsis, Lemma straight, Palea present, well developed, Palea longer than lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Echinochloa stagnina (Burgu millet, bourgou, hippo grass) is a species of Echinochloa widespread in tropical Africa and Asia, with an invasive status in many Pacific islands. It was once one of the major grasses cultivated in the Inner Niger Delta of the Niger River. It was cultivated by the Fulani people, who used the seeds as food, and to make both alcoholic and nonalcoholic beverages.

It tolerates floods well, and has been replanted in Africa, where it has helped to control erosion and provides hay for animals. A traditional food plant in Africa, this little-known grain has potential to improve nutrition, boost food security, foster rural development and support sustainable landcare.