Uppersides of wings have a dark brown ground colour, with yellowish spots or markings. Males are territorial, defending their territory from a perch usually in a patch of sunlight.
Wingspan 44 - 48mm (male), 46 - 52mm (female).
There are generally two broods, with a possible partial third brood in some years. Ova laid usually singly on the underside of leaves of various grasses, and hatch within 8 - 23 days. Overwinters either as laravae or pupae.
Late April to September, with highest numbers in July and August.
This butterfly has undergone a large expansion in the north of Scotland since 1970, extending eastward through Moray and Aberdeenshire, and northward to Caithness. On the west coast, its range now extends to north west Sutherland. It was first reported from Lewis by John Randall in 2003, where it has since established a thriving colony in Lewis Castle grounds, Stornoway.