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Stem 2–5° high; leaves linear or linear-lanceolate, entire, usually glabrate above; heads oblong, canescent, 2–3´´ long—Minn. to Neb., and westward.

Whitened woolly throughout; leaves lanceolate, the upper mostly entire, the lower usually cut-lobed, toothed or pinnatifid, the upper surface sometimes glabrate and green; heads campanulate, mostly sessile in narrow panicles.—Dry banks, Sask. to Mich., Ill., Tex., and westward.

Leaves soft-pubescent when young, becoming glabrate; leaflets rhombic-obovate or ovate, unequally cut-toothed, 1–3´ long, the terminal one cuneate at base and sometimes 3-cleft; flowers pale yellow.

Pubescent or glabrate; stem slender, simple, with few large heads terminating slender branchlets; leaves lanceolate, very acute, narrowed to a sessile base, sparingly serrate or serrulate; scales linear-attenuate, equal, mostly herbaceous; rays blue.—N. Dak. and westward.

Very variable.—Var. nùda, Gray; with sparse and loose pubescence, green and soon glabrate rigid leaves, and short bracts.—Var. spinulòsa, Gray; a canescent form with aristately prolonged and rigid bracts.—Var. aristàta, Gray; loosely hairy and green, or becoming glabrous, with narrowly linear bracts 2–3 times the length of the flowers.