Chenopodium L.

9. Chenopodium L. Chenopodium L., Sp. Pl.: 218 (1753); Kowal, Monogr. Bot.1 87-163 (1954); Brenan, Kew Bull. 1956: 165-167 (1956); Aellen in Hegi, Fl. Mitteleuropa III, 2: 576-578 (1960); Scott, Bot. Jahrb. Syst. 100: 205-220 (1978); Wilson, Nuytsia 4: 139- 180 (1983). Blitum L. (1753). Roubieva Moq. (1834). Teloxys Moq. (1834). Annual herbs, sometimes perennial herbs, shrubs or small trees, with vesicular or glandular hairs, or glabrous, gynomonoecious. Leaves alternate. Flowers in cymose, sometimes glomerulate clusters, in axillary and terminal spiciform or paniculate inflorescences; flowers bisexual or sometimes pistillate; perianth lobes 3-5(-6-8), often keeled or winged, sometimes with fringed appendages, in fruit rarely becoming succulent or basally indurated; stamens 5-3(-0); ovary horizontally flattened; stigmas Z(-3-5). Fruit enclosed in the perianth; pericarp membranous, free or adherent to the horizontal, oblique or vertical seed; embryo annular, hippocrepiform. Zn: 18, 32, 36, 54, 72. Three subgenera: subg. Ambrosia A. J. Scott, annuals or sometimes perennials, glandular hairy, rarely glabrous; inflorescence cymose, flowers solitary or in small loose glomerules; perianth dry; ca. 30 spp. in tropical and subtropical regions. Subg. Chenopodium, annuals, perennials, or woody, mealy of vesicular hairs at least in younger parts; inflorescence mostly of dense glomerules arranged paniculately or spicately; perianth i dry, never really succulent; ca. 100 spp., mostly temperate to subtropical. Subg. Blitum (L.) Hiitonen, annuals or perennials, almost glabrous; inflorescences of dense, aggregated glomerules arranged spicately or paniculately, perianth usually becoming red and fleshy in fruit stage; six spp., N hemisphere, subtropical to temperate.Published as part of Kuehn, U., 1993, Chenopodiaceae, pp. 253-281 in The Families and Genera of Vascular Plants 2, Berlin, Heidelberg :Springer-Verlag on page 26