The sexes are similar and have a wingspan of 30–40 millimetres (1.2–1.6 in). The forewings are dark metallic green with 6 vivid red spots (sometimes the spots are merged causing possible confusion with other species such as Five-spot Burnet). Occasionally the spots are yellow or even black. The hindwings are red with a blackish fringe. The adults fly on hot, sunny days from June to August,[Note 1] and are attracted to a wide variety of flowers such as knapweed and scabious as well as the larval food plants bird’s foot trefoil and clover. The species overwinters as a larva.
The larva is plump and hairy with variable markings, usually pale green with rows of black spots. It pupates in a papery cocoon attached to foliage.