White-legged damselfly (male)

P. pennipes is about 32 millimetres (1.3 in) long. Mature adults differ from most other blue damselflies in having expanded white edges to the tibiae, paired black markings down most of the abdomen, broad pale brown double antehumeral stripes, wider head and a pale brown pterostigmata.

The male has a blue abdomen that is often pale and usually has a greenish thorax. The female is a very pale yellow-green colour with black markings.