This species was first described by Edward Meyrick, using specimens collected by George Hudson at Mount Holdsworth, and named Simaethis ministra.

[3] In 1928 George Hudson discussed this species under that name in his book The butterflies and moths of New Zealand.

[2] The male holotype specimen, collected at Mount Holdsworth, is held at the Natural History Museum, London.

Forewings suboblong, costa moderately arched anteriorly, apex obtuse, termen slightly rounded, somewhat oblique; dark bronzy-fuscous; five very undefined irregular transverse shades of white irroration, first three rather curved or bent, fourth forming a clear white spot on costa beyond middle and then a fine silvery quadrangular loop passing behind a transverse linear discal mark of white irroration, fifth straight, interrupted above middle; two or three silvery-metallic scales before termen above middle: cilia white with dark-fuscous shade (imperfect).

Hindwings light fuscous, becoming darker towards termen; dorsal half with scattered white scales; a well-marked irregular white streak extending across dorsal half of wing from disc at ¾ nearly to tornus, its lower half approximated to termen; cilia white, with fuscous subbasal and post-median shades.