Fl. Bor.-Amer. 1: 319. 1803.
Aerial shoots 5-30 (-35) cm, from short caudices on rhizomes, rhizomes primarily horizontal. Basal leaves 1-5 (-7), ternate; petiole 1-10 cm; terminal leaflet sessile, obtriangular, (0.5-) 0.7-1.8 (-2.2) × 0.5-1.3 cm, base cuneate, margins crenate to broadly serrate on distal 1/3, apex obtuse to truncate, surfaces villous to nearly glabrous; lateral leaflets usually 1×-lobed or parted; ultimate lobes 4-15 mm wide. Inflorescences 1-flowered; peduncle villous; involucral-bracts 2-3, 1-tiered, simple, ± similar to terminal leaflets of basal leaves, obtriangular, 3-cleft, 0.5-2.5 cm, bases distinct, cuneate, margins crenate to broadly serrate, surfaces villous to nearly glabrous; segments 3, oblanceolate to obovate; lateral segments unlobed, 2-8 mm wide. Flowers: sepals 4-7, white or tinged blue or abaxially white, proximally blue, and adaxially white, broadly elliptic to ovate, (7-) 8-20 × 4-9 mm, abaxially hairy, adaxially glabrous; stamens 70-80. Heads of achenes spheric; pedicel 4-18 cm. Achenes: body obovoid, 2-2.5 × ca. 1 mm, not winged, densely woolly; beak straight, 1-2.5 mm, glabrous. 2n=16.
Phenology: Flowering spring–summer (May–Aug).
Habitat: Streamsides, meadows, rocky slopes
Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.W.T., Ont., Que., Sask., Yukon, Alaska, Colo., Idaho, Mont., Oreg., Utah, Wash., Wyo., Asia
"broadened" is not a number.