Leaf blades hairy or glabrous. Scapes glabrous or hairy. Inflorescences: sheath length usually 0.5-0.75 times diam. of flower head; outer involucral bracts 0.5-0.75 times length of flower head. Flowers monomorphic: stigmas papillate, pollen coarsely reticulate; calyx hairy throughout or on ribs only. 2n = 18. Flowering summer. Gravelly tundras, flood plains, lakes and seashores, alpine meadows; 0-1200 m; Greenland; Man., Nfld. and Labr., N.W.T., Nunavut, Ont., Yukon; Alaska, Colo.; Eurasia. The population of subsp. sibirica in Colorado is found on Hoosier Ridge. Plants with calyces hairy throughout and hairy scapes appear in eastern North America east of approximately 100°W longitude mixed with plants with hairy calyx ribs and glabrous scapes. Plants from this area have been called var. labradorica; there is no taxonomic reason for this recognition (C. Lefèbvre and X. Vekemans 1995).