They used to both be classified in the Orchis genus, but Green winged was split away, based on molecular evidence, and placed in the Anacamptis genus. They both show significant, often attractive, colour variations from purple through to pink and white, but they do not seem to hybridise much with any other species. There is though a hybrid between the two, Anacamptorchis morioides, which is an easily remembered name. Unfortunately there are no records for this hybrid since the mid - 1970s on the BSBI database and only a handful before that, so what a challenge to find it and since there is less chance statistically of success than seeing the Ghost Orchid, Britain's rarest orchid (that at least appeared in 2009).
I started out by looking on the BSBI database for monads (1 km squares) where both orchids occurred in Oxfordshire and its surrounding counties, then looked at the individual records to see if they were close enough to be sympatric (ie grow close together). I came up with 18 possible locations with the hotspot around Stroud in Gloucestershire (curiously also a hotspot for the Butterfly orchid hybrid).
Yesterday therefore I set off to that hotspot to share my day with golfers, dogwalkers (lots of them and the mess they leave - one woman had 9 dogs), horse riders and the odd off road cyclist, to look for the impossible, concentrating on orchids with spotted leaves and veined sepals. Disappointingly the 1970s record is still the latest.
I started at Minchinhampton Common where both orchids grow quite close together, but only the Early purples were in flower.
I did find one orchid which I wondered about - unpotted leaves,spur a little less than 10mm and sepals gathered into a hood. But there was no veining, so I concluded it was simply natural variation of a regular Early purple.
Though to the west, Selsey Common, proved more interesting. Green-winged were more advanced and in places the two species grew very close together, the nearest being 20 cm apart.
I spent quite a time watching a tachinid fly (I think, based on the wing pattern) thoroughly exploring a Green-winged orchid, waiting to see if it might, just might, detach a pollinia. Sadly just as the moment approached, so did an uncontrolled, yappy dog which blundered into the orchid and the fly. Harry was the dog's name I think, and imbecile that of the dog owner.