The basal angiosperm Hedyosmum orientale (Chloranthaceae) has a seemingly primitive reproductive morphology and a reduced perianth structure in female flowers. Liu et al. study class B gene homologs and find that the development of the perianth does not rely on B homeotic function. The results suggest that Hedyosmum AP3-like genes have an ancestral function in specifying male reproductive organs and that the activity of the encoded PI-like proteins is highly conserved between Hedyosmum and Arabidopsis. Moreover, the C-terminal region appears to be important for the function of Hedyosmum PI-like genes.
