In Europe, it is found in the north of Norway and Sweden and on rare occasions in northern Finland.

It is also found in North America, specifically in Alaska, Canada, and the Rocky Mountains, Washington, Montana and on Greenland.

C. nastes is dark grey green with grey-black margins and red fringes.

The under surface of the forewing is impure whitish, with greenish-yellow scales, the rose-red fringes are conspicuous, the hindwing is yellowish green, lighter at the margin, the white median spot is bordered with red and distally to it is placed a diffuse red spot, the rose-red fringes are broader than on the forewing.

The female has a somewhat lighter under surface and on the forewing some small black submarginal spots.