Plants annual, usually monoecious (in some species, staminate flowers rare). Stems usually erect, not fleshy. Inflorescences terminal and axillary, ± long, cylindric spikes or panicles; axillary inflorescences similar to terminal ones, but shorter. Pistillate flowers: tepals usually (3–) 5. Utricles transversely dehiscent (except A. bouchonii Thellung and some forms of A. spinosus and A. obcordatus).

Distribution

North America, Central America, South America, one species perhaps native to Europe, into other regions

Discussion

Species ca. 20 (14 in the flora).

Selected References

None.

mucronulate;emarginate;obtuse;emarginate;obtuse;acute +
Sergei L. Mosyakin +  and Kenneth R. Robertson +
Linnaeus +
rounded +  and narrowly cuneate +
orbiculate +  and linear +
persistent +
triangular +, deltate +, subulate +, linear +, lanceolate +  and ovate +
North America +, Central America +, South America +, one species perhaps native to Europe +  and into other regions +
peripheral +
hypogynous +
minute +  and small +
not +  and dehiscent +
reduced +
crispate +, undulate +, plane +  and entire +
scarious +  and membranaceous +
cylindric +
rudimentary +
Sp. Pl. +  and Gen. Pl., ed. +
1753 +  and 1754 +
brown +, reddish-brown +  and black +
lenticular +  and subglobose +
cylindric +
nearly +, simple +  and branched +
prostrate +  and decumbent +
not fleshy +
slender +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Acanthochiton +, Acnida +, Albersia +, Amblogyna +, Euxolus +, Mengea +, Sarratia +  and Scleropus +
Amaranthus subg. Amaranthus +
Amaranthus +
subgenus +
distinct +
subequal +
indurate +, membranaceous +, chartaceous +  and scarious +
walled +  and 3(-5)-veined +
tuberculate +  and rugose +
elongate-ovoid +, ovoid +  and globose +
membranaceous +
pubescent +  and glabrous +