Perennials, (5–)20–150+ cm; taprooted (rootstocks sometimes woody, branched; stolons produced in some taxa). Stems usually 1, usually erect, usually branched distally, sometimes throughout, sometimes scapiform, glabrous or hairy (induments often complex, see discussion). Leaves basal, basal and cauline, or cauline; petiolate or sessile; blades mostly elliptic, lanceolate, oblanceolate, oblong, or spatulate, margins entire, denticulate, or dentate [laciniate to pinnatifid] (faces glabrous or hairy, induments often complex, see discussion). Heads borne singly or in corymbiform, paniculiform, thyrsiform, umbelliform, or nearly racemiform arrays. Peduncles (terminal and axillary) not inflated, often bracteate. Calyculi 0 or of 3–13(–16+), deltate to lanceolate or linear bractlets (in 1–2+ series; sometimes intergrading with phyllaries). Involucres hemispheric or campanulate to cylindric, 3–9[–12+] mm diam. Phyllaries 5–21(–40+) in 2+ series, lanceolate to linear, subequal to unequal (reflexed in fruit), margins usually little, if at all, scarious, apices obtuse to acute or acuminate. Receptacles flat, pitted, glabrous, epaleate. Florets 6–150+; corollas usually yellow, sometimes white or ochroleucous, sometimes tinged with cyan or red, rarely orange (then often drying scarlet or purplish). Cypselae usually red-brown or black (tan in H. horridum), usually ± columnar or prismatic, sometimes ± urceolate (slightly bulbous proximally and narrower distally) or nearly fusiform, not distinctly beaked, ribs (or grooves) usually 10, faces glabrous; pappi persistent (fragile), of 20–80+, distinct, white, sordid, stramineous, or rufous, ± equal or unequal, barbellulate bristles in 1–2+ series. x = 9.