This species was first described from Rhenanie, Germany by Hoppner in 1916 and was initially considered a probable hybrid. It is named in honour of F. Wirtgen, an eminent 19th century German botanist and is a member of the D. traunsteineri group of the genus Dactylorhiza.
D. wirtgenii is not a widespread species being found only in France and Germany where it is extremely rare and as with most hygrophilous members of the genus, is threatened by drainage and eutrophication. It is a species which grows exclusively in alkaline bogs and fens and although most usually grows at lower altitudes, in eastern France it can be found up to 900 metres in the foothills of the western Alps. A further threat to its future is also one shared by other of the rarer members of its genus and this is the problem of absorption by its more vigorous cousins, notably D. majalis and D. incarnata.
The pictures accompanying this text are all from the same population and it will be seen that inflorescence and individual flower characteristics can be variable, particularly the size and density of the flower head. Flowers may be plain or heavily marked, lateral lobes slightly folded back and central lobe prominent. The overall plant is however more uniform, being quite tall, spindly with a stem that shades purple towards the top, often heavily so. The leaves are few in number, cauline and may be unmarked or lightly spotted. The difficulties in accurately identifying Dactylorhiza species are well documented and this species is no exception, with many populations known to have been influenced by several other taxons, sometimes as diverse as D. elata and D. traunsteineri. The pictures are from the Chartreuse region of South east France and date from the first week of June.
D. wirtgenii is not a widespread species being found only in France and Germany where it is extremely rare and as with most hygrophilous members of the genus, is threatened by drainage and eutrophication. It is a species which grows exclusively in alkaline bogs and fens and although most usually grows at lower altitudes, in eastern France it can be found up to 900 metres in the foothills of the western Alps. A further threat to its future is also one shared by other of the rarer members of its genus and this is the problem of absorption by its more vigorous cousins, notably D. majalis and D. incarnata.
The pictures accompanying this text are all from the same population and it will be seen that inflorescence and individual flower characteristics can be variable, particularly the size and density of the flower head. Flowers may be plain or heavily marked, lateral lobes slightly folded back and central lobe prominent. The overall plant is however more uniform, being quite tall, spindly with a stem that shades purple towards the top, often heavily so. The leaves are few in number, cauline and may be unmarked or lightly spotted. The difficulties in accurately identifying Dactylorhiza species are well documented and this species is no exception, with many populations known to have been influenced by several other taxons, sometimes as diverse as D. elata and D. traunsteineri. The pictures are from the Chartreuse region of South east France and date from the first week of June.
