Some relatively rare Taraxacum species of the sections Palustria and Celtica occurring in the province of Friesland are discussed. During the development of the plant five different stages can be distinguished, each with a different leaf morphology. This has led to the description of a number of superfluous species. The observation and comparison of cultivated plants may therefore lead to the synonymisation of a considerable number of names. Within the Taraxacum nordstedtii group of the section Celtica a number of different forms can be recognised when comparing cultivated plants and subjecting them to a genetic analysis.