Description: Thallus is a flattened, obovate to elongate, light brown sac, with a narrow stipe, to 13 cm (5 in) tall and 0.8 cm (0.3 in) wide, attached by an inconspicuous discoidal holdfast. Habitat: This species grows in abundance along the margin of kelps, particularly Laminaria longipes, in the low intertidal of semi-exposed habitats.