The name perfectly describes this damselfly and makes them quite easy to spot, even in flight, as the bright blue dot on the end of the tail shows well in sunlight. They can be found all along the river and around the main lake, especially by the southern bridges. They are around in May to August. The photograph below shows the male, in all blue markings.

Female damselflies can have many colour variations, the normal colour for this female is green-blue, as in the one shown below the male. The one below shows an immature female. Clearly she has a blue tail, but the rest of her is pinky-orange. She is called 'rufescens'. Below her, is the 'violacea' (violet) form.

The one below is the Rufescens-obsoleta form, the mature form of the Rufescens one above (the pink and blue one). It's all very confusing...