Ray corollas white. Disc corollas: indurate portions shiny, glabrous. Pappi: outer of inconspicuous, well-developed setae, inner of 15-27 bristles. Flowering May-Jul(-Aug). Prairies, open and dry slopes, often with sagebrush; 1000-2600 m; Alta., Sask.; Colo., Kans., Mont., Nebr., N.Dak., S.Dak., Wash., Wyo. A report of var. pumilus from Yukon is based on a misidentification of Erigeron caespitosus.