Aristolochia

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Aristolochia
Calico Flower (Aristolochia elegans)
Calico Flower (Aristolochia elegans)
Plant Info
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Piperales
Family: Aristolochiaceae
Genus: Aristolochia
L.

Species
See text

Aristolochia is a large genus of plants with over 500 species, belonging to the Birthwort family (Aristolochiaceae).

This is a genus of evergreen and deciduous woody vines and herbaceous perennials. They are widespread and occur in the most diverse climates, but not in Australia.

The smooth stem is erect or somewhat twining.

The simple leaves are alternate and cordate, membranous, growing on leaf stalks. There are no stipules.

File:Aristolochia.littoralis2web.jpg
Calico Flower (Aristolochia elegans) - leaves
Ornamental Aristolochia

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. These flowers have a specialized pollination mechanism. The plants are aromatic and their strong scent 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 appearance of the flowers gives rise to the genus' common name Dutchman's pipe.

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.

The fruit is dehiscent capsule with many endospermic seeds.

Some species are commonly called Dutchman's Pipe, Pipevine (Aristolochia macrophylla), Birthwort (Aristolochia clematitis), and Virginia Snakeroot (Aristolochia serpentaria). The first three names come from the shape of the flowers, which resembles a pipe and a birth canal. Birthwort was given to women in labor to expel the placenta, but since aristolochic acid is a poison, it sometimes resulted in the mother dying. Nevertheless, aristolochic acid is said to cure wounds or snakebites in a spectacular way. Decoctions of birthwort stimulate the production of white corpuscles and increase their activity. Furthermore, birthwort contains a disinfectant which drains off fluid from the wound. Birthwort was therefore highly regarded by the ancient Egyptians, Greeks and Romans.

Nonetheless, epidemiological and laboratory studies have shown the toxicity of herbal remedies containing plant species of the genus Aristolochia. Herbal compounds containing Aristolochia are classified as a Group 1 carcinogen by the International Agency for Research on Cancer.

Many species of Aristolochia are food for larvae of Swallowtail butterflies.

Some reference books state that the Latin name Aristolochia was developed from Greek etymons meaning aristos, "best", and locheia, "childbirth" or "childbed".

Species

Aristolochia gigantea

References