This species is distinguished from Johnny Jump-up (Viola pedunculata) by its paler lemon-yellow and slightly smaller flowers (the lowest petal being 6–16 mm long). Like Johnny Jump-up, the face of the petals has dark brown veins at the base of the lowest petal and reddish-brown patches on the back of the upper petals. A more important difference is that this species has basal leaves. Basal and cauline leaves are different. Basal leaves are generally green, glabrous, sometimes shiny above and sometimes purplish below, roundish with a tapered base and acute or obtuse tips. Cauline leaves are lanceolate to triangular with a heart-shaped, truncate or tapered base and acute tip.
Note: Viola purpurea is a notoriously difficult species and differentiating between the subspecies is challenging even for experts.