Females, such as shown to the left, have more orange on their FWs than do Karners. Seeing Karner Blues again reaffirms how beautiful they are. Their wings expand about an inch. Males are deep bluish-purple above with narrow black rims and white fringes, while females have wider dark borders and orange crescents internally edging the HW fringe. The wings are pale gray beneath with arcs of black spots, and rows of orange and satiny blue markings along the margins.
Females are a trifle larger than males, and have more extensive orange areas on the underside.
Unfortunately, because it is endangered and occurs so locally, most people will not have the opportunity to know and enjoy it without considerable effort. A view of Karner Blue habitat. Karner Blues were discovered in the 1860s at London, Ontario, and in New York's Karner barrens. In 1944, famed novelist and lepidopterist Vladimir Nabokov finally scientifically named the Karner Blue, which had previously been confused with other blues. Alexander B. Klots coined its English name in his Field Guide to the Butterflies in 1951.