Analysis of the CYC/TB1 class of TCP transcription factors in basal angiosperms and magnoliids.

Flower monosymmetry contributes to specialized interactions between plants and their insect pollinators. In the magnoliids, flower monosymmetry is exhibited only in the Aristolochiaceae (Piperales). Aristolochia flowers develop a calyx-derived monosymmetric perianth that enhances pollination success by a flytrap mechanism.