O. leochroma is an eastern Mediterranean representative of the O. tenthredenifera group, whose name is a reference to its hairy lip, thought to resemble a lions mane. Until recently this taxon was considered to be within the natural varietal range of O. villosa but later studies and perhaps most importantly, work carried out in Crete by Delforge (2005) has now determined that O. villosa is not a single species but a polytipic taxon which has now been split into six additional new species. (O. dictynnae, O. dimidiata, O. sancta-marcella, O. ulyssea , O. korae and O. leochroma)

Of all these species, O. villosa is the latest to bloom in mid March though it has much the shortest season, being largely finished by early April, when the longer lasting O. leochroma (that first appeared at the same time) will still be in full flower. As a result of the reclassifications, O. leochroma is the most widely distributed, being found in continental Greece, the Aegean and Turkey. The biggest overlap in range of this species is with O. villosa and in Crete particularly, differentiating the two in the field is far from straightforward, as although there are some formally described morphological differences, these do not seem to be unique and can prove inconclusive in the field.

Typically O. leochroma exhibits a longer lip when measured from stigmatic cavity to appendage, more intensely coloured perianth and a hairier border. It is further said to be a larger and darker flower but although O. villosa is often paler, both species appear to produce darker and lighter morphs. In reality, the only sure way to separate the species is is by study of their flowering period and where possible, identification of their differing pollinators. The authors acknowledge that this species description is unsatisfactory but until greater clarity is available we cannot be more precise. The pictures are from Crete and the Aegean dating from the first week of April.