Annual herb up to 2 m. high, upright, rarely spreading, normally much branched, green or slightly red-tinged, mealy especially on young parts but soon sparingly so or glabrescent. Leaves (in outline) ovate or deltoid-ovate, mostly 2.5-15 cm. long and 1.5-10 (-12) cm. wide, with more or less numerous irregular often coarse sharp teeth (7-60 or more on each margin). In¬ florescences composed of divaricately branched cymes up to 5 cm. long from upper leaf-axils and also sometimes terminal. Flowers greenish or red-tinged, minute, about 0.8-1.5 mm. in diameter. Sepals 5, papillose on margins and particularly towards base outside, each with a rather narrow blunt raised green keel towards apex only. Stamens 5. Pericarp easily scraped off seed. Seeds (Fig. 2/4, p. 3) black, rather shining,. 1.5-2 mm. in diameter, bluntly keeled; testa under microscope marked with very close minute irregularly but not radially elongate pits which are sinuose and irregularly branched. Fig. 3.