hybrid swarm or one species
B.J.M. Zonneveld (Mon, 11 Jun 2007 00:38:56 PDT)

In my opinion taxonomist comsider it in most/all cases as one species if
two populations gradually convert to its other. First it shows they are
interfertile, secondly the hybrids seem to be fertile too So they must
be considered as two (extreme) poulations that form one species