Dysphania (plant)

Dysphania
Dysphania anthelmintica, American Wormseed
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Core eudicots
Order: Caryophyllales
Family: Amaranthaceae
Subfamily: Chenopodioideae
Tribe: Dysphanieae
Genus: Dysphania
R.Br.
species

about 43 species, see text

Dysphania is a plant genus in the family Amaranthaceae, distributed worldwide from the tropics and subtropics to warm-temperate regions.

Description

Inflorescence of Epazote (Dysphania ambrosioides)

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 (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 1-5 tepals connate only basally or fused to form sac, 1-5 stamens, and a superior ovary with 1-3 filiform stigmas.

Fruits and seeds of Dysphania botrys

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.[1]

Photosynthesis pathway

All species of genus Dysphania are C3-plants with normal leaf anatomy.[2]

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.[3]

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.[2]

Dysphania was first published in 1810 by Robert Brown in Prodromus Florae Novae Hollandiae, p. 411-412.[4] Type species is Dysphania littoralis R.Br.. The genus name Dysphania derives from the Greek dysphanis, meaning obscure, probably referring to the inconspicuous flowers.

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..

Illustration of Dysphania botrys
Dysphania carinata

The genus Dysphania consists of 5 sections with about 43 species:

Excluded species: Teloxys aristata (Syn. Dysphania aristata (L.) Mosyakin & Clemants, Chenopodium aristatum L.).[6]

Vernacular names

Usage

Epazote or Mexican Tea (Dysphania ambrosioides) and American wormseed (Dysphania anthelmintica) are medicinal herbs, Epazote is used as tea. They are also used als insecticides.[7]

Some species of Dysphania are used as dye.[7][8]

References

  1. ↑ Erich Oberdorfer, Theo Müller (1983): Pflanzensoziologische Exkursionsflora. 5. ed., Ulmer, Stuttgart, ISBN 3-8001-3429-2, p.342
  2. 1 2 Gudrun Kadereit, Evgeny V. Mavrodiev, Elizabeth H. Zacharias, Alexander P. Sukhorukov (2010): Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the origin of C4 Photosynthesis. In: American Journal of Botany, 97(10), p. 1664–1687.
  3. ↑ Pertti Uotila (2011): Chenopodiaceae (pro parte majore). – In: Euro+Med Plantbase – the information resource for Euro-Mediterranean plant diversity. Dysphania. Euro+Med Plantbase, retrieved 30 November 2011.
  4. ↑ First publication scanned at Biodiversity Heritage Library
  5. ↑ Tropicos, retrieved 30 November 2011.
  6. ↑ "Teloxys aristata". Germplasm Resources Information Network (GRIN). Retrieved 26 November 2015.
  7. 1 2 Dysphania ambrosioides at Liber Herbarum, retrieved 30 November 2011.
  8. ↑ Dysphania schraderiana at Liber Herbarum, retrieved 30 November 2011.
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