An altitude specialist, over 750m and nearly always a lot higher. The uppersides of both sexes are brown, the male being plain brown and having no blue scales or lunules at all, whereas the female is indicated by a few uph marginal orange lunules. The defining characteristic of eumedon is the unh white streak from the cell spot, along v5 to the post-discal spot, and sometimes beyond. The underside markings are more distinct in the female, which also usually has a deeper brown ground colour. It is usually tied closely to the larval hostplant, various species of Geranium, principally Wood Crane's-bill (Geranium sylvaticum).

The converse is usually true, in that if it is not sitting on a Geranium, it is probably not eumedon. For an altitude butterfly, it tends to emerge quite early, from May onward, which may explain the degree of wear on the males in some of these photos taken in July.

In the new European taxonomy, this species now has the scientific name Aricia eumedon.

observations

a male, rather worn.

rather fresher but still missing a chunk out of the hindwing.

a male.

an interesting Y-shaped discal spot on the unh.

a female sitting on G. sylvaticum.

a mating pair, female on the right. This shows the contrast between the undersides of the sexes, the male being rather greyer in ground colour and having rather less well-developed marginal lunules. The female is also fresher as is nearly always the case for mating pairs. They are on, I believe, G. sylvaticum.