- Latin synonym: Polyommatus amandus
- Family: Gossamer-winged Butterflies – Lycaenidae
- Subfamily: Blues – Polyommatinae
- Wing span: Small, 28–36 mm (1.1–1.4 in.). Males slightly larger than females.
- Wing upper side: Males shiny sky-blue, margins unclearly-edged black, wing veins close to margins black. Females darker blue, edges dark brown or wings completely dark brown. Hind wing margin with red blotches.
- Wing underside: Light grey (male) or light brown (female) with white-edged black blotches. Red blotches especially on margin of hind wing. Basal area of wings turquoise.
- Habitat: Meadows, grazing land, roadsides and other open landscapes.
- Flying time: Mid-June–July. Second generation (end-July–August) possible.
- Overwintering form: Caterpillar.
- Larval foodplant: Meadow vetchling (Lathyrus pratensis) and tufted vetch (Vicia cracca).
Amanda’s blue is quite common across central and southern Finland and can be recognized by the red blotches along the margin of the underside of the hind wing, but it lacks shiny blue patterns and white patches, stripes or wedges.
The species is tightly tied to dense stands of its foodplants. Males fly around their hostplants to find females. Females lay their eggs individually on the leaves of the host plant. The larvae have glands which secrete nourishing, sugary fluid that ants like to lick. In this way ants are attracted to the larvae, and their presence protects them.