O. ferrum-equinum was first described from Samos by Desfontaines in 1807 and its common name of the Horseshoe Ophrys derives from the characteristic specular pattern. This species is highly variable and several varieties have been formally recognized, many of which can be found growing alongside the nominate race, a factor which causes some authorities to be sceptical of their taxonomic validity.

O. ferrum-equinum var. anafiensis was described in 2001 by B. Biel and as its varietal name suggests was  first found on the Cycladic island of Anafi. Although most numerous here, it has subsequently been discovered on other islands of the Cyclades, as well as Kos, Kephalonia and Karpathos. It is a notably small flowered variety as compared to the nominate species. In Kephalonia it may be found growing alongside O. ferrum-equinum but elsewhere less so. It is however distinguishable from type by a smaller, more rounded  perianth and sepals which are conspicuously green veined and usually uni-coloured pink with only minimal traces of green. The lip is always more or less three lobed, sometimes forming small, very hairy protuberences.

The speculum is variable and can range from isolated droplets to a more complex pattern consisting of a typical horseshoe embellished with upward extensions that reach the basal area and stretch across the shoulders. Even in less elaborate specimens there is usually a trace of steely blue either side of the stigmatic cavity. This feature can sometimes be difficult to discern without close inspection. The photographs comes from the islands of Kephalonia and Kos dating from the first week of April.