The genus Isotrema is usually included here as Aristolochia subgenus Siphisia, but might be a valid genus.<ref name="POWO"/><ref name="Isotrema">Template:Cite journal</ref> It contains the species with a three-lobed calyx.<ref name="Isotrema"/>
Aristolochia is a genus of evergreen and deciduous lianas (woody vines) and herbaceous perennials. The smooth stem is erect or somewhat twining. The simple leaves are alternate and cordate, membranous, growing on leaf stalks. There are no stipules.
The flowers grow in the leaf axils. They are inflated and globose at the base, continuing as a long perianth tube, ending in a tongue-shaped, brightly colored lobe. There is no corolla. The calyx is one to three whorled, and three to six toothed. The sepals are united (gamosepalous). There are six to 40 stamens in one whorl. They are united with the style, forming a gynostemium. The ovary is inferior and is four to six locular.
These flowers have a specialized pollination mechanism. The plants are aromatic and their strong scent<ref>"sometimes with a very disagreeable odour" remarks the Royal Horticultural Society, Dictionary of Gardening.</ref> attracts insects. The inner part of the perianth tube is covered with hairs, acting as a fly-trap. These hairs then wither to release the fly, covered with pollen.
The fruit is dehiscent capsule with many endospermic seeds.
The common names Dutchman's pipe and pipevine (e.g. common pipevine, A. durior) are an allusion to old-fashioned meerschaum pipes at one time common in the Netherlands and northern Germany. Birthwort (e.g. European birthwort A. clematitis) refers to these species' flower shape, resembling a birth canal.
Aristolochia was first described by the 4th c. BC Greek philosopher and botanist Theophrastus in his ‘’Inquiry of Plants’’ [IX.8.3], and the scientific name Aristolochia was developed from Ancient Greekaristos (άριστος) "best" + locheia (λοχεία), childbirth or childbed, relating to its known ancient use in childbirth.<ref>Template:Cite web</ref><ref>Template:Cite web</ref> The Roman orator Cicero records a different tradition, that the plant was named after an otherwise unknown Greek person with the name Aristolochos, who had learned from a dream that it was an antidote for snake bites.<ref>Cicero, On Divination 1.10.16</ref>
Many species of Aristolochia are eaten by the caterpillar larvae of swallowtail and other butterflies, thus making the larvae and butterflies unpalatable to most predators. Lepidoptera feeding on Aristolochia species include:
Eastern Festoon (Allancastria cerisyi) – known from numerous pipevine species <ref>Tolman, T., 1997. Butterflies of Britain & Europe. Harper Collins</ref>
Southern Festoon (Zerynthia polyxena) – known from numerous pipevine species
Spanish Festoon (Zerynthia rumina) – known from numerous pipevine species
In Australia the invasiveAristolochia littoralis is fatal to the caterpillars of Ornithoptera euphorion and O. richmondia and threatens to displace their proper host, A. tagala.
The Bencao Gangmu, compiled by Li Shi-Zhen in the latter part of the sixteenth century, was based on the author's experience and on data obtained from earlier herbals; this Chinese herbal classic describes 1892 "drugs" (with 1110 drawings), including many species of Aristolochia.<ref>Template:Cite book</ref> For 400 years, the Bencao Gangmu remained the principal source of information in traditional Chinese medicine and the work was translated into numerous languages, reflecting its influence in countries other than China. In the mid-twentieth century, the Bencao Gangmu was replaced by modern Materia Medica, the most comprehensive source being Zhong Hua Ben Cao (Encyclopedia of Chinese Materia Medica), published in 1999.<ref>Health Department and National Chinese Medicine Management Office (ed.). Zhong Hua Ben Cao, 3–460–509. Shanghai Science Technology Publication. 1999.</ref> The Encyclopedia lists 23 species of Aristolochia, though with little mention of toxicity. The Chinese government currently lists the following Aristolochia herbs: A. manshuriensis (stems), A. fangchi (root), A. debilis (root and fruit), and A. contorta (fruit), two of which (madouling and qingmuxiang) appear in the 2005 Pharmacopoeia of the People's Republic of China.
In traditional Chinese medicine Aristolochia species are used for certain forms of acute arthritis and edema.<ref>Bensky, D., et al. Chinese Herbal Medicine: Materia Medica, Third Edition. 2004. pp 1054-55.</ref><ref name=vanherweghem>Template:Cite journal</ref><ref>Template:Cite journal</ref>
Aristolochia taxa have also been used as reptile repellents. A. serpentaria (Virginia snakeroot) is thus named because the root was used to treat snakebite, as "so offensive to these reptiles, that they not only avoid the places where it grows, but even flee from the traveler who carries a piece of it in his hand".<ref>Freeman-Mitford, A. B. The Bamboo Garden (1896) quoted in Alice M. Coats, Garden Shrubs and Their Histories (1964) 1992, s.v. "Aristolochia".</ref> A. pfeiferi,<ref>Template:Cite book</ref> A. rugosa,<ref>Template:Cite book</ref> and A. trilobata<ref>Template:Cite journal</ref> are also used in folk medicine to treat snakebites.
Aristolochia has been shown to be both a potent carcinogen and kidney toxin. Herbal compounds containing Aristolochia are classified as a Group 1carcinogen by the International Agency for Research on Cancer.<ref>ACS (2006)</ref> Epidemiological and laboratory studies have identified Aristolochia to be a dangerous kidney toxin; Aristolochia has been shown to be associated with more than 100 cases of kidney failure.<ref>Template:Cite journal</ref> Furthermore, it appears as if contamination of grain with European birthwort (A. clematitis) is a cause of Balkan nephropathy, a severe renal disease occurring in parts of southeast Europe.<ref>Template:Cite journal</ref> In 2001 the UK government banned the sale, supply and importation of any medicinal product consisting of or containing a plant of the genus Aristolochia.<ref>Statutory Instruments 2001 No. 1841. The Medicines (Aristolochia and Mu Tong etc.) (Prohibition) Order 2001. http://www.legislation.gov.uk/uksi/2001/1841/made</ref> Several other plant species that do not cause themselves kidney poisoning, but which were commonly substituted with Aristolochia in the remedies, were prohibited in the same order.<ref>Template:Cite web</ref>
Aristolochic acid was linked to aristolochic acid-associated urothelial cancer in a Taiwanese study in 2012.<ref>Template:Cite journal</ref> In 2013, two studies reported that aristolochic acid is a strong carcinogen. Whole-genome and exome analysis of individuals with a known exposure to aristolochic acid revealed a higher rate of somatic mutation in DNA.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> Metabolites of aristolochic acid enter the cell nucleus and form adducts on DNA. While adducts on the transcribed DNA strand within genes are detected and removed by transcription-coupled repair, the adducts on the non-transcribed strand remain and eventually cause DNA replication errors. These adducts have a preference for adenine bases, and cause A-to-T transversions. Furthermore, these metabolites appear to show a preference for CAG and TAG sequences.
Garden history
Due to their spectacular flowers, several species are used as ornamental plants, notably the hardy A. durior of eastern North America, which was one of John Bartram's many introductions to British gardens; in 1761 Bartram sent seeds he had collected in the Ohio River Valley to Peter Collinson in London, and Collinson gave them to the nurseryman James Gordon at Mile End to raise. The vine was soon adopted for creating for arbors "a canopy impenetrable to the rays of the sun, or moderate rain", as Dr John Sims noted in The Botanical Magazine, 1801.<ref>Quoted in Coats (1964) 1992.</ref>
_(2).jpg){kind=link}
_(14522217697).jpg){kind=link}
