Callirhoe comprises nine species and two varieties distributed
from northeastern New Mexico through Florida including northeastern
Mexico. The genus exhibits variation in sex expression possessing
gynodioecy and monecy. Gynodioecy is rare in the Malvaceae yet three
of the nine species of Callirhoe are gynodioecious and a
fourth exhibits functional gynodioecy. Preliminary results of
morphology and sequence data derived from the nrDNA ITS region, will
be presented to examine the phylogenetic relationships of the taxa.
Breeding system data will be mapped onto the species phylogeny to
estimate the pathway of breeding system evolution in the genus.
Key words: Breeding system evolution, Callirhoe, Gynodioecy, ITS, Malvaceae, Phylogenetics