Plants usually annual, usually monoecious. Leaves with Kranz anatomy. Staminate flowers with calyx lobes not crested. Pistillate flowers lacking or rarely with a perianth (in A. covillei), enclosed by a pair of bracteoles. Bracteoles cuneate to ovate or obovate, united at least to 1/2 of length, faces with tubercles or crests or smooth. Seeds: radicle lateral or superior.


United States, Mexico.


Species 28 (23 in the flora).

Selected References