Pigweed

Stems erect to ascending, much-branched to simple, 1-10.5 dm, farinose. Leaves nonaromatic; petiole 0.2-9 cm; blade narrowly to broadly lanceolate, rhombic, ovate, or triangular, 1.2-12(-15) × 0.5-7.5(-9) cm, base cuneate to truncate, margins serrate, irregularly dentate, or entire, often with 2 basal lobes, apex acute to acuminate, farinose. Inflorescences glomerules in compound spikes, 5-17 cm; glomerules irregularly rounded, 4-7 mm diam.; bracts absent. Flowers: perianth segments 5, distinct nearly to base; lobes ovate to deltate, 0.7-1.5 × 0.7-1.3 mm, apex obtuse, farinose, often prominently keeled, covering fruit at maturity or not; stamens 5; stigmas 2, 0.3-0.5 mm. Achenes or utricles depressed-ovoid; pericarp adherent or nonadherent near stylar base, alveolate-rugose. Seeds round, 1-2 mm diam., margins rounded; seed coat brown to black, honeycomb pitted. 2n = 36.

Varieties 6 (6 in the flora): North America, introduced widely.