Review of Ophrys apifera x O. insectifera (beefly orchid) in the British Isles, with validation of the hybrid name Ophrys x pietzschii

The natural hybrid between the bee orchid (Ophrys apifera Huds.) and fly orchid (Ophrys insectifera L.) was first found in Leigh Woods, N. Somerset, v.c. 6 in 1968, but not recognised as such until the publication of a description of the artificial synthesis of this cross, made in Germany. However, the name given, Ophrys×pietzschii Kümpel, was invalid as no specimen was indicated as holotype. A type is now selected and the name is formally validated as Ophrys×pietzschii Kümpel ex F.J. Rumsey & H.J. Crouch. Subsequent finds of this rare hybrid are documented and a revised description is given. Aspects of the hybrid’s formation, particularly the directionality of the hybridisation process, were investigated by DNA sequencing of maternally inherited plastid markers. The biology, future prospects, and conservation of the single extant British population are considered and discussed.