O. hystera was first described from Imathia (Greece) by Kreutz and Peter in 1985 and is a member of the widespread and increasingly confusing O. mammosa group of Ophrys.
 
This species is very similar to O. mammosa but although sharing many morphological characteristics there are key differences. The first of these being the size of the plant, which significantly exceeds that of O. mammosa in all its parts. O. hystera is a robust, often tall plant which can carry up to ten large flowers in a loose inflorescence. The colouration of these flowers can be significant, with O. hystera normally being less drab and often brightly marked with a prominent yellow/orange marginal band.

A second and important aid to identification is the size of the basal swellings, which in O. hystera are invariably substantial but often huge and completely dominating the lips appearance. A further differentiating characteristic is the stigmatic cavity which is always dark, with a pair of bluish/white pseudo-eyes and a distinctive white and grey central spot (specular stage) between them. The O. mammosa group of Ophrys is very well represented in the northern half of Greece, where hybridization is widespread and intermediate populations common. This interbreeding along with the O. mammosa groups vast propensity for natural variation, can significantly complicate identification. O. leucophthalma is a species that can easily be confused with O. hystera, particularly as they are both late flowerers and share similar habitat preferences. The former may however be separated by its all white specular stage and thicker white lining to the speculum.

The illustrations are from the Peloponnese and northern Greece, dating from the second week of May.