Science Fair Project Encyclopedia
The Aristolochiaceae, or the Birthworth family, are a family of flowering plants with 7 genera and about 400 species belonging to the order Piperales.
Some newer classification schemes, such as the Update of the Angiosperm Phylogeny Group, place the family Aristolochiacea in the order Piperales, but it is still quite common, though superseded, for the Aristolochiaceae to be assigned their own order (Aristolochiales).
The bizarre flowers are large to medium-sized, growing in the leaf axils. They are bilaterally or radially symmetrical.
Many members of Aristolochia and some of Asarum contain the toxin aristolochic acid, which discourages herbivores and is known to be carcinogenic in rats. Aristolochia itself is carcinogenic to humans.
Pipevine swallowtail butterflies lay their eggs on pipevine (Aristolochia species), and the larvae dine on the plant but are not affected by the toxin, which then offers the adult butterfly protection against predators.
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details