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 oder sessile glandular hairs and therefore with aromatic scent. 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 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, 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
numbers reported are 2n=16, 18, 32, 36, and 48.
Photosynthesis pathway
All species of genus Dysphania are C3 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 Dysphaniabelongs 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:
Dysphania sect. Adenois Mosyakin & Clemants: 15 species, native in South and Middle America, now distributed worldwide from the tropics to warm-temperate regions:
* Dysphania ambrosioides Mosyakin & Clemants, Epazote, Mexican-tea: native in North- and South America, naturalized in other continents.
* Dysphania chilensis Mosyakin & Clemants Spegazzini; Chenopodium ambrosioides var. vagans J.T.Howell; Dysphania andicola Mosyakin & Clemants, Dysphania sooana : native in Argentina and Chile.
* Dysphania multifida Mosyakin & Clemants, Syn.: Chenopodium multifidum L., Roubieva multifida Moq., Teloxys multifida W.A.Weber, Dysphania macrocarpa, Cut-leaf goosefoot, small-leaved wormseed: native in South America, introduced from the tropics to warm-temperate regions.
* Dysphania oblanceolata Mosyakin & Clemants
* Dysphania tomentosa Mosyakin & Clemants
* Dysphania venturii Mosyakin & Clemants
Dysphania sect. Botryoides Mosyakin & Clemants: with 3 subsections:
* Dysphania sect. Botryoides subsect. Botrys Mosyakin & Clemants: with 9 species, worldwide, native in southern North America, northern South America, southern Eurasia and Africa.
** Dysphania botrys, Jerusalem-oak, feather-geranium: native from Middle Europa to China, naturalized or cultivated in other temperate regions.
** Dysphania nepalensis Mosyakin & Clemants, in Central Asia
** Dysphania procera Mosyakin & Clemants
** Dysphania pseudomultiflora Verloove & Lambinon : In South Africa.
** Dysphania schraderiana
* Dysphania sect. Botryoides subsect. Incisa Mosyakin & Clemants: With 1 species in southwestern North America and in South America:
** Dysphania dissecta Mosyakin & Clemants
Dysphania sect. Dysphania, with 8 species in Australia:
* Dysphania glandulosa Paul G.Wilson, in Australia
* Dysphania glomulifera Paul G.Wilson, in Australia
* Dysphania kalpari Paul G.Wilson, in Australia
* Dysphania littoralis R.Br., in Australia
* Dysphania plantaginella F.Muell., in Australia
* Dysphania platycarpa Paul G.Wilson, in Australia
* Dysphania rhadinostachya A.J.Scott, in Australia
* Dysphania simulans F.Muell. & Tate ex Tate, in Australia
* Dysphania sphaerosperma Paul G.Wilson, in Australia
* Dysphania valida Paul G.Wilson, in Australia
Dysphania sect. Orthospora Mosyakin & Clemants: with 7 species in New Zealand and Australia, some species introduced in other regions:
* Dysphania carinata : native in Australia, naturalized in other continents.
* Dysphania cristata, Syn.: Blitum cristatum F.Muell., Chenopodium cristatum : native in Australia, naturalized in other continents.
* Dysphania melanocarpa Mosyakin & Clemants, black crumbweed
* Dysphania pumilio Mosyakin & Clemants, Syn.: Chenopodium pumilio R.Br., Teloxys pumilio, Clammy goosefoot, small crumbweed: native in Australia, naturalized in other continents.
