20. Atriplex Linnaeus, Sp. Pl. 2: 1052. 1753; Gen. Pl. ed. 5, 472. 1754.
Orach, saltbush [ancient Latin name]
Stanley L. Welsh
Herbs or shrubs, annual or perennial, monoecious or dioecious, often with bladderlike hairs that collapse to form silvery or scurfy (mealy) vesture, less often with elongate trichomes. Leaves persistent or tardily deciduous, alternate, partially opposite, or opposite, sessile or petiolate; blade entire, serrate, or lobed, with venation either of Kranz-type or normal dicotyledonous type, axillary buds inconspicuous or lacking. Inflorescences axillary or terminal; flowers borne in axillary clusters or glomerules, or in terminal spikes or spicate panicles. Staminate flowers with 3-5-parted calyx, ebracteate; stamens 3-5. Pistillate flowers lacking perianth, pistil naked, or in few species with (1-)3-5-lobed perianth, commonly enclosed within pair of foliaceous bracteoles; stigmas 2. Fruiting bracteoles enlarged in fruit, of various shapes and variously connate or not, thickened, and appendaged; pericarp free, tightly enclosed in the fruiting bracteoles. Seeds flattened, mainly vertical; radicle inferior, lateral, or superior. x = 9.
Species ca. 250 (62 in the flora): worldwide, mainly in subarctic, temperate, and subtropical regions.
Many species of Atriplex are halophytic, others occupy soils low in dissolved particulates.
Prior to the 1900s, the genus Suckleya was treated within Atriplex, but its obcompressed fruiting bracteoles are quite unlike anything in Atriplex, and the plants were recognized as a distinct genus.
Bassett, I. J., C. W. Crompton, J. McNeill, and P. M. Taschereau. 1983. The Genus Atriplex (Chenopodiaceae) in Canada. Ottawa. [Agricu. Canada Monogr. 31.] Brown, G. D. 1956. Taxonomy of American Atriplex. Amer. Midl. Naturalist 55: 199-210. Hall, H. M. and F. E. Clements. 1923. The phylogenetic method in taxonomy: The North American species of Artemisia, Chrysothamnus, and Atriplex. Publ. Carnegie Inst. Wash. 326. Hanson, C. A. 1962. Perennial Atriplex of Utah and the Northern Deserts. M.S. thesis. Brigham Young University. McNeill, J., I. J. Bassett, C. W. Crompton, and P. M. Taschereau. 1983. Taxonomic and nomenclatural notes on Atriplex L. (Chenopodiaceae). Taxon 32: 549-556. Taschereau, P. M. 1972. Taxonomy and distribution of Atriplex species in Nova Scotia. Canad. J. Bot. 50: 1571-1594. Turesson, G. 1925. Studies in the genus Atriplex. Acta Univ. Lund, n. s. 21: 1-15. Welsh, S. L. 1995. Names and types of perennial Atriplex Linnaeus (Chenopodiaceae) in North America selectively exclusive of Mexico. Great Basin Naturalist 55: 322-334.