Critical notes on species ofHieracium(Asteraceae) reported as common to Sweden and Britain

Abstract

All species of Hieracium sectt. Hieracium, Vulgata (incl. Bifida) and Oreadea originally described from the Nordic countries, but reported in recent accounts as occuring in the British Isles, have been scrutinised based on specimens and published descriptions. Out of 29 species stated as occurring in Britain and native to Fennoscandia, only four are confirmed (H. caesiomurorum, H. oistophyllum, H. pellucidum and H. triviale). These are all species with wide distributions in Fennoscandia and northern Europe and their occurence in Britain is thus not surprising. In addition, the first British occurrence of the widespread European species H. neopinnatifidum is reported. Apart from the above four, H. caesitium, H. diaphanoides and H. austrinum (H. scanicum) are possibly also native to both areas, although the material examined is not fully conclusive. In addition, at least a few species occur as aliens in both Sweden and Britain, but a further twelve need to be critically compared. Most of the Nordic names used for British plants are found to be based on misidentifications and the species concerned will have to be described and named anew. It is concluded that it is not good practice to borrow names of Hieracium species from distant areas without critically comparing types, authentic specimens and relevant literature. Only a very few species of this genus have distributions that stretch into several countries or across major water bodies. (Less)