Chenopodium atrovirens Rydb.

Chenopodium atrovirens has been reported for Washington but we have seen no specimens. Reports of C. carnulosum Moquin-Tandon from Texas are, at least in part, this species. We have seen no reliable North American records of this southern South American species.

Stems erect to ascending, usually much-branched, 0.7-6.5 dm, moderately to densely farinose. Leaves nonaromatic; petiole 0.5-1.5 cm, usually markedly upward curved; blade ovate, broadly oblong, oblong, oval, or occasionally triangular, prominently 3-veined, 1-3 × 0.4-2.2 cm, 1.5-3 times longer than wide, thick, base rounded to cuneate, margins entire or occasionally with basal lobe, apex obtuse or rounded, farinose abaxially. Inflorescences glomerules in terminal and axillary paniculate spikes, 2-8 × 1-1.5 cm; glomerules maturing unevenly; bracts linear, 2 × 0.1 mm. Flowers: perianth segments 5, distinct nearly to base; lobes obovate, 0.8-0.9 × 0.6-0.8 mm, apex rounded or emarginate, carinate, farinose, not covering fruit at maturity; stamens 5; stigmas 2, 0.1 mm. Achenes or Utricles ovoid; pericarp adherent or nonadherent, smooth. Seeds 0.9-1.3 mm diam., margins acute; seed coat black, rugulate. 2n = 18.

Alta., B.C., Sask.; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wyo.

Fruiting mid summer-fall.

Open dry sandy areas and other disturbed sites; 100-3400m.

Chenopodium fremontii S. Watson var. atrovirens (Rydberg) Fosberg