XVI International Botanical Congess
Species in the Hawaiian silversword alliance have radiated into a wide variety of morphological forms and ecological habitats. Molecular evidence indicates that many species may be the product of reticulate evolution following an initial radiation. Species are largely out crossing and hybrids among widely divergent lineages are readily obtained in the laboratory. Further, hybrids among species are frequently observed in sympatry. We have examined the genetic variation present across the hybrid zones of three hybrid combinations in apparently different stages of evolution: a newly established hybrid zone, a long established hybrid zone, and a hybrid that has become reproductively isolated and is now considered a distinct species. Our findings are discussed in terms of the plants genetics, cytology and ecology.