Our smallest resident butterfly is easily overlooked, partly because of its size and dusky colouring, but partly because it is often confined to small patches of sheltered grassland where its sole foodplant, Kidney Vetch, is found.

Males set up territories in sheltered positions, perching on tall grass or scrub. Once mated, the females disperse to lay eggs but both sexes may be found from late afternoon onwards in communal roosts, facing head down in long grass. The butterfly tends to live in small colonies, and localised in distribution.

Size and Family

  • Family: Blues
  • Size: Small 
  • Wing Span Range (male to female): 20-30mm

Caterpillar Foodplant

The sole foodplant is Kidney Vetch (Anthyllis vulneraria). The larvae live only in the flower heads where they feed on developing anthers and seed.



    Rare but found on sheltered, warm grassland habitats which have Kidney Vetch. Habitats include; chalk and limestone grassland, coastal grasslands and dunes and man-made habitats such as; quarries, gravel pits, road embankments and disused railways.