Seligeria pusilla is a rare species with a highly scattered distribution, having occurrences in northern Alaska, Ellesmere Island, and in temperate eastern North America from Minnesota south and east to Tennessee. It has linear leaves with a relatively narrow costa that does not fill the apex. The acute leaf tips have cells that are thin-walled and somewhat longer than wide. The plants are light green and have a delicate aspect to them. Seligeria brevifolia and S. acutifolia both have differentiated perichaetial leaves whereas S. pusilla has capsules surrounded by leaves similar to (although somewhat longer than) those farther down the stem.