Annual or perennial, green and glabrous, white-mealy or glandular-pubescent herbs, with alternate petioled entire sinuate-dentate or pinnately lobed leaves. Flowers very small, green, perfect, sessile, bractless, clustered in axillary or terminal, often panicled or compound spikes. Calyx 2-5-parted or 2-5-lobed, embracing or enclosing the utricle, its segments or lobes herbaceous or slightly fleshy, often keeled or ridged. Stamens 1-5; filaments filiform or slender. Styles 2 or 3; seed horizontal or vertical, sometimes in both positions in different flowers of the same plant, firmly attached to or readily separable from the pericarp; endosperm mealy, farinaceous; embryo completely or incompletely annular. [Greek, goose-foot, from the shape of the leaves.]

About 60 species, mostly weeds, of wide geographic distribution. Besides the following, some 5 others occur in the western parts of North America. Type species: Chenopodium rubrum L.

* Embryo a complete ring; plants not glandular.

Leaves white-mealy on the lower surface (except in some races of No. 1).

Leaves or some of them mostly sinuate-toothed or lobed.

Sepals strongly keeled in fruit.

Pericarp firmly attached to the seed; stem erect, tall.

1.

C. album.

Pericarp readily detached from the seed; stem low.

2.

C. incanum.

Sepals not keeled in fruit; stem decumbent.

3.

C. glaucum.

Leaves mostly entire.

Leaves linear to oblong, short-petioled.

4.

C. leptophyllum.

Leaves broadly ovate, long-petioled.

5.

C. Vulvaria.

Leaves green and glabrous or nearly so on both surfaces when mature.

Leaves oblong or ovate-oblong, entire.

6.

C. polyspermum.

Leaves, at least the lower, sinuate, toothed or incised.

Stamens 5; calyx not fleshy.

Pericarp readily separable from the seed.

Leaves oblong or lanceolate; calyx-lobes scarcely keeled.

7.

C. Boscianum.

Leaves triangular-hastate; calyx-lobes keeled.

8.

C. Fremontii.

Pericarp firmly attached to the seed.

Flower-clusters, at least the upper, longer than the leaves.

9.

C. urbicum.

Spikes loosely panicled in the axils, the panicles shorter than the leaves.

10.

C. murale.

Stamens only 1 or 2; calyx slightly fleshy, red.

12.

C. rubrum.

Leaves very coarsely 2-6-toothed.

11.

C. hybridum.

Leaves broadly triangular-hastate, entire or merely undulate.

13.

C. Bonus-Henricus.

** Embryo an incomplete ring; plants glandular aromatic.

Leaves ovate or oblong, pinnately lobed; flowers in long loose panicles.

14.

C. Botrys.

Leaves lanceolate; flowers in continuous or interrupted spikes.

15.

C. ambrosioides.