Common names: Jungle rice, Junglegrass, Swampgrass, arrocillo (S), zacate de agua (S), metebravo (S), blé du Dekkan (F) Echinochloa colona (L.) Link. is a smooth, tufted annual 30 75 cm high, usually decumbent and rooting at the lower nodes, green to purple with an inflorescence of short spikes in an alternate arrangement on the main axis. The stem is flattened, often red purple at the base, usually swollen at the nodes. Leaf sheath is smooth, margins free in upper part and basal portion of sheath is often tinged with red. Leaf blade is smooth, flat, linear lanceolate, flaccid, up to 25 cm long, 3 7 mm wide, sometimes transverse purple bands. The inflorescence of E. colona is green to purple, ascending panicle, 6 12 cm long with 4 8 simple, short, compact branches 1 3 cm long, 3 4 mm wide, ascending or appressed about half their own length apart. Spikelets are ovate to broad ovate, acute, 2-3 mm long and crowded into 4 rows along one side of the branch, nearly sessile. Fruit, a caryopsis about 1.3- 2 mm long.
E. colona normally grows under dryland conditions ; does not thrive in continuously flooded soils. Like Echinochloa crus-galli, young plants resemble rice, which makes hand weeding difficult early.