[Panicum colonum L.; Echinochloa glabrescens Kossenko]
(nat) Jungle-rice
Annuals; culms tufted, usually reddish purple, erect, ascending or decumbent at base, sometimes rooting at lower nodes, 20-60 cm tall, sometimes nodes conspicuously swollen and usually geniculate, compressed, lower internodes often exposed. Sheaths 3-7 cm long, compressed, keeled, glabrous; ligule absent; blades green or sometimes with transverse purple bands, flat, 4-10 cm long, 3-8 mm wide, often undulate, margins occasionally scabrous, apex acute. Inflorescences paniculate, usually 5—10(—15) cm long, green or purple- tinged, racemes several, 1-2 cm long, the lower ones up to 1 cm apart, the upper ones crowded, rachis scaberulous, pedicels short, scaberulous; spikelets crowded, usually in ca. 4 rows, (1.5—)2.5—3 mm long, acute to cuspidate, rarely with a subulate point up to 1 mm long; glumes ovate, his- pidulous, apex acute, first glume 1.2-1.5 mm long, 3-nerved, second glume 2.5-3 mm long, 7-nerved; first lemma similar to second glume, first palea ovate, ca. 2 mm long, glabrous; second lemma broadly ovate, ca. 2 mm long, glossy. Caryopsis whitish, broadly ovate, 1.7-2 mm long, flat on one side. [2n = 30, 36, 48, 52, 54, 56, 72, 96, 108, 130.] Apparently native to the Paleotropics, but now widely distributed; in Hawai‘i naturalized in wet or seasonally wet, disturbed areas, 0-280 m, on all of the main islands. First collected on 0‘ahu in 1835 (Nuttalls.n., BISH).—Plate226.