|Abstract||Erect tall annual, usually branched. Leaves simple, with 2 free stipules, in the lower part of the stem opposite, in the higher part spirally arranged, long-petioled, palmate, 3—11-foliolate. Flowers (♂) (♀) or mostly (♂♀). Male flowers in short, dense cymes, which are united into lax, foliate, terminal panicles, very shortly pedicelled. Tepals 5, free, oblong, membranous, imbricate. Stamens 5, epitepalous; filaments erect and short in bud, linear, with a narrowed apex; anthers comparatively large, basifixed, 2-celled, cells opening longitudinally, rudimentary ovary absent. Female flowers solitary in the axil of a small, primary, membranous, entire bract closely enveloping the ovary, each enveloped by a spathaceous, conspicuous, acuminate, secondary bract. Perianth absent. Ovary sessile, 1-celled; style central; stigmas 2, sessile, long, filiform, caducous. Ovule solitary, pendulous. Achene closely enveloped by the much enlarged, secondary bract, broadly oval, with a concave rimmed base, much compressed, faintly keeled on the lateral margins; pericarp smooth, hard, crustaceous, easily splitting into two halves; albumen unilateral, scanty, fleshy; embryo large, horseshoe-shaped; cotyledons large; radicle long.|
Distr. Monotypic, native of Central Asia, cultivated in tropical Asia, naturalized in N. America.