Notes on some Taraxacum (Asteraceae) from Ireland including description of four new species in section Celtica

Abstract

In the context of substantial recent collections of Taraxacum in the Irish Midlands, this paper records some additions to our knowledge of Irish dandelions. Four new species in Taraxacum section Celtica A. J. Richards are described, T. aesculosum, T. gaelorum, T. hibernicola and T. inclinorum; only the first is known outside Ireland, where the first three are quite widespread. Taraxacum pietii-oosterveldii H. Øllgaard, a relative of T. nordstedtii Dahlst., is newly recorded for Ireland from six Irish vice-counties; it also has not yet been recorded from Britain. The rare British wetland species T. anglicum Dahlst. and T. palustrisquameum A. J. Richards are recorded from Ireland for the first time, and the Spanish species, T. nietoi A. J. Richards, apparently extinct in Britain, has persisted in an Irish locality for 10 years. A new variety of T. ronae L. J. Margetts which lacks leaf spotting is described as var. immaculatum A. J. Richards; this variety seems more common in Ireland than the type. Taraxacum ronae is a common and widespread species in Ireland.