Annual herb, erect or less commonly ascending, up to c. 2 (-3) m in height, not infrequently reddish-tinted throughout. Stems stout, branched, angular, glabrous or thinly to moderately furnished with short or long multicellular hairs (increasingly so above, especially in the inflorescence). Leaves glabrous, or thinly pilose on the lower margins and underside of the primary nervation, long-petiolate (petioles up to 15 cm but even then scarcely exceeding the lamina), lamina broadly lanceolate to rhomboid or ovate, 3-19 (-30) x 1.5-8 (-12) cm, gradually narrowed to the blunt to subacute mucronulate tip, attenuate or shortly cuneate into the petiole below. Flowers in yellowish, green, reddish or purple axillary and terminal spikes formed of cymose clusters, which are increasingly closely approximate upwards, the terminal inflorescence varying from a single spike to a broad, much-branched, panicle up to c. 45 x 25 cm: in length and breadth, the ultimate spike not infrequently nodding; male and female flowers intermixed throughout the spikes. Bracts and bracteoles deltoid-ovate to deltoid-lanceolate, pale-membranous, acuminate and with a long, pale to reddish-tipped, erect arista formed by the stout, excurrent, yellow or greenish midrib, subequalling to much exceeding the perianth. Perianth segments (3-)5, 1.5-3.5 mm, lanceolate or oblong, acute-aristate or the inner sometimes blunt in the female flowers, only the midrib at most greenish. Stigmas (2-) 3, erect, flexuose or recurved, c. 0.75-1.25 mm. Capsule subglobose to ovoid or ovoid-urceolate, 2-3 mm, circumscissile, with a moderately distinct to obsolete “neck”, lid smooth, longitudinally sulcate, or sometimes rugulose below the neck. Seed black and shining or pale, compres¬sed, 0.75-1.25 mm, almost smooth centrally, faintly reticulate around the margins.