Northern Marble is a species of butterfly that occurs in northern North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

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It is mostly white with black markings on the topside of the forewing tips and body. The underside has greenish-grey veins especially in the hindwing.
Wing span is from 24 to 36 mm.

Flight season in North America is from late May to mid-July.

Larvae on Draba

Draba

Draba is a large genus of cruciferous plants, commonly known as whitlow-grasses. There are over 400 species:*Draba abajoensis Windham & Al-Shehbaz*Draba × abiskoensis O.E.Schulz*Draba × abiskojokkensis O.E.Schulz...

and Cruciferae.