So far, all eight tepalled yellow crocuses Nothoscordums are dialystemon. With six, Nothoscordum felipponei. Under Ipheion this species was "Ipheion sellowianum". It is not impoosible that the six tepal species produce abnormal eight tepalled flowers but so far it is an easy way to tell them apart. The white 'Rolf Fiedler' must be distributed by its perpetrator. I suspect it is slow offsetting and this is why it is not more widespread. I make the formal proposal to all reading this that we propagate 'Rolf Fiedler' from seed. With time more 'Jessie's will come up and msot important we will be producing clean stock from seed. Tristagma and ipheion have the same basic features. a tube and six tepals. The difference among the species in shape is by pressure fromthe polliantors for eons. Who could say Babianas pygmaea, ringens and spathacea belong to the the same genus? Even so, it is so evident they do that no one could doubt it. Same with Gladioli abbeviatus, watermeyeri and papilio. And many other examples.