O. leptomera was first described by Delforge from Euboea Island (Greece) in 2000 and its name refers to the overall slenderness of the plant. It's a member of the large O. oestrifera group and is synonymous with O. oestrifera subsp.leptomera (Kreutz), a title which some authorities still prefer to refer to it as.
It is a relatively spindly, lax-flowered plant but may nonetheless carry an inflorescence of up to 10 medium to large flowers, this being a key distinguishing feature. Perhaps the most consistent characteristic however is the perianth colouration which is usually either green or green washed purple, though examples of plants with the more ubiquitous oestrifera group full purple are not uncommon. In these latter cases differentiating O. leptomera from other members of the group can be difficult and separating it from O. bicornis particularly so. As with this latter species, speculum pattern is normally full but unremarkable, with horns, that although variable are usually long and outward pointing.
This is an extremely localized species which is nowhere common but which maybe encountered practically anywhere in its pan-Hellenic range and possibly beyond. It has been recorded both to the north and south of the Gulf of Corinth but is perhaps at its most frequent in the region to the east of Athens. The pictures come from the southern Epirus region and date from the first week of May, at which time they were just starting their flowering cycle.
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