Hello @mercantour
The nomenclature of Crocus is quite complicated. C. albiflorus has been listed as a synonym of C. vernus at POWO for a long time, although it is not the same species. The reason for this is that C. vernus has obviously been a collection of different species, some of which can only be distinguished by genetic analysis and some of which are originally escaped garden hybrids.

Also in the German distribution maps (floraweb) both species are included with different distribution maps. The very recent identification literature (Rothmaler) now only lists C. vernus (s.str.), but now means the clan that was previously called C. albiflorus. The former C. vernus has been split into 5 (wild) species, one of which is C. vernus s.str. (syn. C. albiflorus).

I have now made this taxon split, but without creating an atlas for the individual minor species. As a result, all species previously labelled C. vernus have now reverted to the C. vernus complex and need to be re-determined. (Which I find very helpful, as most observations are not C. vernus in the new sense, but often garden escapees).

After merging C. albiflorus and C. vernus (s.str.) only the former C. albiflorus are now named C. vernus.

I think this is a good solution overall. Since we now follow the new nomenclature and at the same time have got rid of many garden plants.