Author:
Qjure
Book:
Qjurious
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Info
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3-622.72.00
Aristolochiaceae
English: Birthwort family; Snake root family.
Name: Aristolochia derives from the Greek words aristos meaning "the best" and 'lochéia' meaning ' childbirth', for the old use in promoting uterine contractions.
Content: aristolochic acids, carcinogenic, mutagenic, nephrotoxic
Genera: Aristolochia, Asarum, Euglypha, Heterotropa, Pararistolochia, Saruma, Thottea.
Content: oxytocin.
DD: Phase 7, Chlorine, Fluorine; Carbon series.
Botany
Lianas, climbers, vines; rarely herbs or shrubs.
Root: rhizotamous.
Stems terete; often with corky bark on older stems.
Leaves: alternate; distichous; simple; entire; cordate to linear with sagittate or hastate lobes, occasionally 3-lobed, often palmately veined; pseudostipules sometimes present.
Inflorescences fasciculate, racemose or rhipidia or helicoidal cymes, axillary or cauliflorous.
Flowers: bisexual; zygomorphic; 3 merous; tube of enlarged, petaloid sepals; petals lacking; stamens 5 to 6, single whorl fused to styles to form lobed gynostemium; ovary inferior, twisted; carpels 5-6, syncarpous, locules 5-6, placentation submarginal, ovules usually numerous; purple, red, yellow or pink; often mimicking rotting flesh.
Pollen: monosulcate; inaperturate; adaxial prophylls.
Pollination: by flies, entrapped and later released.
Fruit: brown capsule, dehiscent, septicidally or septifragally, acropetally or basipetally, opening into a basket-like shape. Seeds: numerous, winged or with sticky aril; embryo small, weakly dicotyledonous; endosperm abundant, oily, sometimes starchy.
Pollination
The structures of the flowers are similar to the flytrap mechanisms found in the carnivorous genus Nepenthes. However, whereas Nepenthes digests the insects as a means of adapting to environments with poor soil, Aristolochia and Isotrema simply make use of them for pollination. The flies are attracted by the 'alluring', putrid scent of the flowers and pass through the smooth, waxy 'slide zone' on the limb of the flower. At the base of this zone they become trapped in the utricle, an inflated part of the perianth, by the retrorse hairs at its entrance. The insects pollinate the stigmas as they enter the utricle, remaining there until the stamens have ripened and deposited pollen on them as the flower withers. Meanwhile the flies are kept alive with supplies of nectar from trichome nectaries that are usually present in the utricle. Most Aristolochia and Isotrema flowers wither after about 24 hours, and as they do so the retrorse hairs that trapped the insects lose their turgidity, releasing them to pollinate more flowers.
Taxonomy
Aristolochiaceae is placed in the order Piperales because it has trimerous flowers, monosulcate or inaperturate pollen and adaxial prophylls. Piperales is close to the monoctyledons because of the trimerous flowers and pollen structure.
Piperales is close to Annonaceae because the flowers have several carpels, oil cells and the well developed petals of Sauruma, although the genera found in Central and South America do not have petals (González, 2000).
The gynostemium, perianth and inferior ovary with many ovules make it similar to Rafflesiaceae.
Cronquist considered it to be in the monofamilial order Aristolochiales.
Aristolochia is a very big genus. In the past many other genus names have been used for it: Ambuya; Cardiolochia; Dasyphonion; Dictyanthes; Diglosselis; Duchartrella; Eimomenia; Einomeia; Einomeria; Endodaca; Endodeca; Endotheca; Enomeia; Eudodeca; Euglypha; Glossula; Guaco; Hexaplectris; Hocquartia; Holostylis; Howardia; Isiphia; Isotrema; Niphus; Pistolochia; Plagistra; Psophiza; Pteriphis; Siphidia; Siphisia; Tropexa.
Bamias Giorgos; Balkan Nephropathy: Evolution of Our Knowledge; World Kidney Forum; American Journal of Kidney Diseases, Vol 52, No 3, September, pp 606-616; 2008.