6.5 to 8 mm. Usually metallic or iridescent green, occasionally blue or brassy. 

Very similar to some other Chrysomelidae species, particularly Chrysolina herbacea.

Good quality close up photographs required. Detailed examination of the specimen may be necessary. The foodplant can be a useful guide to species.

Associated with Alder and usually found in Alder stands by watercourses and in damp woodlands.

Mid-April to late August.

Adults hibernate (sometimes in moss) from late August to mid-April.

Widespread, but local in Britain and less common in the south. 

Rare in Leicestershire and Rutland.