Amaranthus dubius Mart. ex Thell.

Erect, monoecious, annual herb 2 m, sometimes becoming much branched, stout and succulent; stems green to pink, glabrous to sparsely puberulent. Petiole shorter than to longer than blade; blade ovate, rhombic to lanceolate, 2-9(-17) x 1-6(-11) cm, entire or somewhat crenulate. Inflorescence of axillary clusters and drooping terminal spikes or panicles, 5-20(-25) cm long; bracts and bracteoles lanceolate, ovate or obovate, much shorter than tepals, midrib prominent. Male flowers mostly in apical portion of terminal inflorescence; tepals 5, oblong-elliptical, 1.7-2 mm long, often mucronate; stamens 5(4). Female flowers in axillary clusters and on lower portion of terminal inflorescence; tepals 5, oblong, 1.3-2 mm long, obtuse to acute, often emarginate and mucronate; styles 2-3. Utricle indehiscent to circumscissile, subequal to slightly exceeding perianth, 1.5-2.5 mm long, obtuse or truncate at apex, roughly wrinkled or rugulose, smooth below, often with apparent line of dehiscence; seed cochleate-orbicular or lenticular, 0.7-1.1 mm wide, dark reddish-brown or black, lustrous.

A tropical plant. It suits the tropical humid lowlands. It can grow in arid places. In Papua New Guinea it grows between sea level and 1,800 m altitude. It needs a night temperature above 15°C and preferably a day temperature above 25°C. It needs fertile, well-drained soil.

The leaves and seeds are eaten cooked. They are often mixed with bitter leaf (Vernonia) or African eggplant. CAUTION: This plant can accumulate nitrates if grown with high nitrogen inorganic fertilisers and these nitrates are poisonous.

Plants can be grown from seed if the soil is warm. Seeds are small and grow easily. They can be broadcast in a nursery and then transplanted. Cuttings of growing plants root easily.