They are mostlyperennial,herbaceous plants,shrubs, orlianas. The membranous, cordate simpleleaves are spread out, growing alternately along the stem on leaf stalks. The margins are commonly entire. Nostipules are present. Theflowers are large to medium-sized, growing in the leaf axils. They are bilaterally or radially symmetrical.
Some newer classification schemes, such as the update of theAngiosperm Phylogeny Group, place the family Aristolochiaceae in the order Piperales, but it is still quite common, though superseded, for the Aristolochiaceae to be assigned, sometimes with some other families, their own order (Aristolochiales).
The highly reduced plastid genome map of a member of Aristolochiaceae,Hydnora visseri
The completeplastid genome sequence of one species of Aristolochiaceae,Hydnora visseri, has been determined. As compared to thechloroplast genome of its closest photosynthetic relatives, theplastome ofHydnora visseri shows extreme reduction in both size (ca. 27 kilobase pairs) and gene content (24 genes appear to be functional).[9] This Aristolochiaceae species therefore possesses one of the smallest plastid genomes amongflowering plants.[10]
Pipevine swallowtail butterflies lay theireggs on pipevine (Aristolochia species), and thelarvae feed on the plant, but are not affected by thetoxin, which then offers the adult butterfly protection againstpredators.
^Evolution and Diversification of Land Plants by Kunio Iwatsuki and Peter H. Raven, Springer Science & Business Media, 6. des. 2012
^The first fossil Aristolochia (Aristolochiaceae, Piperales) leaves from Austria by Barbara Meller, Article number: 17.2.21A,https://doi.org/10.26879/420, Palaeontological Association, May 2014
