Silene suksdorfii appears to be closely related to S. parryi but differs in its broadly winged seeds, smaller size, cespitose habit, and the prominent purple-septate hairs of the calyx, although the latter occasionally are present in S. parryi. It is very similar to, and in Idaho appears to intergrade with, another alpine species, S. sargentii, which has linear leaves and lacks the purple septa in the hairs and the broad wing on the seeds. It is similar also to S. hitchguirei; see discussion under that species.