Greater Butterfly Orchids

The SWT nature reserve at Keltneyburn is well know as a location for Greater Butterfly orchids but they are also found on West Tempar. In both locations they grow in short vegetation in what might be described as hay meadows although in the case of West Tempar the ground is quite marshy.

They are tall with greenish white flowers and can be distinguished from the Lesser butterfly orchid because their Pollinia are diverging and not parallel (as they are in the Lesser Butterfly orchid). The pollinia are structures in which the pollen grains are gathered together ready to be attached to the pollinators.

They are pollinated by night flying moths such as Golden Spangle, Silver Y and small Elephant hawk-moths. The moths get the pollinia stuck onto their eyes when they are attempting to drink the nectar which is to be found at the end of the long spur. During flight the pollinia swing in position so that they are ready to attach to the stigma of the next flower and fertilise it. Darwin studied the flower and worked out quite a lot of the detail of pollination.

The Greater Butterfly Orchid was once widespread across the UK but is now quite rare.

Pollinators

General diagram of orchid flower structure

Many useful photos on wildflower finder website.

Richard Paul