Meetings of the Royal Botanical Society of the Netherlands

Until recently European records of diploid sexual plants of Taraxacum sect. Taraxacum (= sect. Vulgaria) have been scarce. Den Nits & Sterk (1980, and in preparation) found that sexual dandelions are numerous in Central Europe, where two main areas with an abundance of diploid plants can be distinguished (Jenniskens & Den Nijs, in preparation). Morphologically and ecologically different, sexual individuals hailing from these two areas have been used in crossing experiments. The results show that: – F1 seeds germinate readily; – the morphology of the F j hybrids is intermediate between that of the parents; – the F1 pollen sterility usually equals that of the parents, but may be higher in some cases; – after bee pollination, the F, seed set is 70% up to 100%, which indicates and undisturbed female meiosis in the offspring; – after selling, F1 plants produce vigorous F2 seedlings.