The wings are pure white with a wide black tip on the apexes of the forewings.

[3] Larvae have yellow stripes on the upper part of the green body and has black lumps.

[5] The disappearance of this species coincides with the introduction, in the 1950s, of the small white butterfly (Pieris rapae).

[6] Another reason may be the introduction of a widely introduced agricultural bioagent, the wasp parasitoid, Cotesia glomerata, which was found in the western Canary Islands in May 2006.

The scientific name commemorates Thomas Vernon Wollaston, an English entomologist who has discovered several insect taxa on Madeira.