Selected names in the genus Taraxacum, belonging to T. sect. Erythrocarpa and T. sect. Erythrosperma, published in a series of papers by C. E. Sonck were revised taxonomically. Their types, from Greece (except two from Albania), were compared with material mainly from the Balkan Peninsula deposited at PRA. Ten names are relegated to synonymy. Range extensions (to Italy, Albania, the Former Yugoslav Republic of Makedonija, Bulgaria, Romania, Crimea and Turkey) are reported for ten taxa. Nomenclatural comments are given for T. acutiusculum, T. dialeptum, T. gracilens, T. panhellenicum and T. salonikiense. A lectotype is designated for T. dialeptum.