Platanthera chlorantha, Greater Butterfly-orchid
Platanthera chlorantha has not been doing well lately in Oxfordshire and this sad situation is reflected in other parts of the UK. Weather conditions may be to blame but the plant also has to contend with snail damage. Ash die-back is resulting in increased light levels and thus increasing aggressive plant competition in the herb layer, from plants such as Dog’s-mercury Mercurialis perennis, Cleavers Galium aparine and Nettle Urtica dioica. Habitat maintenance at all the sites where P. chlorantha occurs is active and consistent with the requirements of the plant.
The plant is also probably under-recorded, especially in the Chilterns.
There are past records for Platanthera chlorantha in 27 locations. There are four main sites, Bald Hill at Aston Rowant, Cornbury Park, the BBOWT Warburg Reserve, near Henley, and Greenfield Farm.
Platanthera x hybrida, the hybrid between P. bifolia and P. chlorantha does sometimes appear at the Warburg but no plants were found in 2019.