Dysphania (plant)
Dysphania is a plant genus in the family Amaranthaceae, distributed worldwide from the tropics and subtropics to warm-temperate regions. Description. The species of genus "Dysphania" are annual plants or short-lived perennials. They are covered with stalked or sessile glandular hairs and therefore with aromatic scent (or malodorous to some people). Some species have uniseriate multicellular trichomes, rarely becoming glabrous. The stems are erect, ascending, decumbent, or prostrate and mostly branched. The alternate leaves are mostly petiolate, (the upper ones sometimes sessile). The leaf blade is linear, lanceolate, oblanceolate, ovate, or elliptic, often pinnately lobed, with cuneate  or truncate base, anentire, dentate, or serrate margins. The inflorescences are terminal, loose, simple or compound cymes or dense axillary glomerules. Bracts are absent or reduced. Flowers are bisexual (rarely unisexual), with up to five tepals connate only basally or fused to form sac, one to five stamens, and a superior ovary with one to three filiform stigmata. The fruit is often enclosed in perianth. The membranous pericarp is adherent or nonadherent to the horizontal or vertical, subglobose, or lenticular seed. The seed coat is smooth or rugose. The annular or incompletely annular embryo is surrounding the copious farinose perisperm . Chromosome numbers. Chromosome numbers reported are 2n=16, 18, 32, 36, and 48. Photosynthesis pathway. All species of genus "Dysphania" are C plants with normal leaf anatomy. Distribution. The genus "Dysphania" is distributed worldwide from the tropics and subtropics to warm-temperate regions. In Europe, the species are native, archaeophytes, or naturalized, in the northern regions absent or rarely adventive. Systematics. The genus "Dysphania" belongs to the tribe Dysphanieae in the subfamily Chenopodioideae within the plant family Amaranthaceae. According to phylogenetic research, it is related to genera "Suckleya" and "Cycloloma". "Dysphania" was first published in 1810 by Robert Brown in "Prodromus  Florae Novae Hollandiae", p. 411-412. Type species is "Dysphania littoralis" R.Br.. The genus "Dysphania" primarily comprised 7-10 Australian species. Sometimes they were grouped as an own family, Dysphaniaceae Pax & Hoffmann, or even regarded as members of families Illecebraceae and Caryophyllaceae. In 2002, Sergei L. Mosyakin & Steven E. Clemants extended the genus for the glandular species of "Chenopodium" subgenus "Ambrosia" A.J.Scott. Synonyms for "Dysphania" R.Br. are "Neobotrydium" Moldenke, "Roubieva" Moq. and "Teloxys" Moq.. The genus "Dysphania" consists of four sections with about 40 species: Excluded species: "Teloxys aristata" (Syn. "Dysphania aristata" (L.) Mosyakin & Clemants, "Chenopodium aristatum" L.). Usage. Epazote  or Mexican tea ("Dysphania ambrosioides") and American wormseed ("Dysphania anthelmintica") are medicinal herbs. Epazote is used as a tisane and as an insecticide. Some species of "Dysphania" are used as dye.