Thank you for your answer Peter.
I've seen there are many subspecies indeed. I don't master your flora enough, to express an opinion retaning to these subspecies.
In my country, we have the same problem about the genera Ophrys (Orchidaceae). According to the autors, there are up to 150 species in Europe...but genetically there are 9 species !
Sorr for my English it's not perfect.