O. istriensis was first described from the Istrian peninsula of Croatia by Hertel, Paulus and Weyland in 2016 and so far as is currently known, restricted in range to the municipalities of Rovinj and Bale. It is a member of the O. bornmuelleri group of Ophrys,

This species can be difficult to conclusively identify due to its huge variability. In the absence of fine measurements, perhaps the most significant and constant differentiator is the appendage which is small relative to its cousins and invariably forward pointing, often appearing to be extended as if stalked. Other morphological characteristics such as colouration, lip shape and specular pattern are unreliable as O. istriensis is capable of proficiently imitating its fuciflorid cousins.

O. istriensis is typically a robust plant with up to twelve, large flowers that appear in April, at the same time as the similar O. untchjii, with which it frequently associates. O. medea and O. tetraloniae are smaller flowered but will be at their best only as O. istriensis is fading. Sepal colouration is highly variable, ranging from dark pink (rare) to pure white, with green being the most usual. The stigmatic cavity is conspicuously large, being widest at the base and usually merging into a sizable and concolorous basal field. Basal swellings are always present and these may be significantly proportioned, close set and usually forward pointing unlike those of O. medea which are generally splayed outwards. Although the number of known sites for this species is relatively small, it can occur in significant numbers.

The photos are all from the Bale district, dating from the first week of May 2016.