Species of Poa show an exceptional diversity in breeding systems represented by the occurrence of hermaphroditism to dioecism, with gynomonoecy very frequent among species in South America. Giussani et al. contribute to the understanding of the evolutionary patterns in Poa associated with species sexuality and their current distribution.
Divergence dating provides a temporal context to the evolution of breeding systems. Infrageneric taxonomic categories in New World Poa supersect. Homalopoa can be accommodated to the phylogenetic results in correlation with reproductive system and geography.