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 side by side, a factor which causes some authorities to be sceptical of their taxonomic validity.
O. ferrum-equinum var. anafiensis was described from the Cycladic island of Anafi by B. Biel in
2001. Although most numerous on Anafi, it has subsequently been
discovered on other islands of the Cyclades group as well as 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 perianth with conspicuous green veining
within the sepals and which in mature specimens develop rolled back
margins.The lip is always more or less three lobed, sometimes forming
small, very hairy horns.
The speculum can be somewhat complex and may consist of a full H pattern that produces parallel lines reaching up to the basal area and perhaps stretching across the shoulders. Even in less elaborate cases there is usually a trace of steely blue colouration either side of the stigmatic cavity. The photograph comes from the Ionian island of Kephalonia and dates from the first week of April.
