A medium-size (approx.4.0 cm wingspan robust olive grey-green and black moth that flies in early spring. The basal and terminal areas of the forewings are lighter olive green, with smaller patches along the costa, around the orbicular and reniform spots, with the remainder suffused with black. The amount of black varies considerable, and the illustrated specimen (from Redwater) is about average. The hindwings are dark grey, usually with pale olive in the disc and on the lower margin. The fringes are checkered. The thorax and abdomen are olive and black. Sexes similar, except male antennae bipectinate, female simple. The other two Alberta species of Feralia are more common and widespread. F. comstocki is paler green with greatly reduced dark areas and lighter hindwings; F. jocosa is smaller with darker hindwings, and usually lacks the extensive dark suffusion on the forewings.