The amazing camouflage of the female Brimstone butterfly, Gonepteryx rhamni in Shabden Park, Surrey.

 If you hadn't seen it fly to this bramble stem. one would be unlikely to spot this  female Brimstone butterfly, Gonepteryx rhamni in Shabden Park, Surrey last weekend.

There is a view that the word 'butterfly' originates from the yellow colour of male Brimstones.  The wings of the female are very pale green, almost white, males have yellow-green underwings and yellow upperwings.

The same butterfly feeding on Betony flowers with the pale yellow (almost white) part upper wing exposed.

What a little beauty.
See http://butterfly-conservation.org/1229-1310/brimstone.html for more info' on this and other butterflies and moths in the UK.