Plastid and nuclear variation among apomictic polyploids

Apomicts (plants grown from seeds or spores are produced without fertilization) account for 20–50 % of all species in northern Europe, but both phylogeny and evolutionary processes in apomictic genera remain largely unknown. Tyler and Jönsson use chloroplast sequences and nuclear microsatellites to create an overview of the variation in one of the most species-rich of all plant genera, Hieracium sensu stricto (hawkweed; Asteraceae). Although they find that cpDNA show too little variation and microsatellites are too variable to resolve relationships among species or evolutionary processes, they conclude that both species and sections as defined by morphology are congruent with the molecular data, that gene flow between the sections is rare, and that the tetraploid species may constitute the key to understanding evolution and speciation in Hieracium.