Until recently O. negadensis was a name applied to a small group of similar Ophrys that were locally quite frequent in north west Greece. In 2002 however, Hirth split this taxon into two separate species, reassigning O. negadensis to the O. exaltata group, with O. zeusii becoming a newly described species, still within the O. mammosa family. Although they share very similar habitat preferences, O. negadensis is much the rarer of the two species, occurring at sites in very small numbers and with a significantly more limited range. They may often be found growing together and both share a preference for a degree of shade, as may be found in the clearings and edges of open woodland.

Separating the two species is however straightforward and several characteristics help to differentiate them. Perhaps the most immediately recognizable of these are the petals, which in O. negadensis can be as long as the sepals. Lip pilosity differs, with O. zeusii exhibiting whitish marginal hair only on the shoulders and upper lateral lobes, whilst in O. negadensis, the marginal hair more or less encircles the labellum. The lip of O. zeusii is generally less obviously three lobed and normally more flared, a characteristic which serves to make the yellow margin appear broader and more prominent. A further feature dividing these two taxons is the flowering period,  as although O. negadensis may still be found in early May, it will by this date be considerably past its best and at a time when O. zeusii is only just beginning to appear. The pictures are from the Negades area, dating from the last week of April.