Perennials, 35-110(-150) cm; taprooted, spreading by rhizomes. Stems 1-30(-100), ascending to erect (sometimes reddish brown, sometimes ± brittle), appressed-strigose, sparsely to moderately long-hirsute, eglandular or sparsely to moderately stipitate-glandular, more densely so distally; axillary fascicles absent. Leaves: proximal cauline subpetiolate to sessile, blades oblanceolate, 38-73 cm × 6-15(-18) mm, bases cuneate, margins flat, sparsely serrate, strigoso-ciliate, with a few long cilia proximally, faces moderately long-strigose, eglandular or sparsely to moderately stipitate-glandular; distal sessile (usually spreading, sometimes perpendicular), blades usually narrowly to broadly oblanceolate, rarely obovate or ovate, little reduced distally (not stiff), margins sparsely serrate (not long-ciliate), faces moderately strigose, sparsely to moderately stipitate-glandular. Heads (1-)5-24, usually in open to congested corymbiform arrays, sometimes borne singly, on long peduncular branches. Peduncles 5-35 mm, short-hispido-strigose, sometimes stipitate-glandular; bracts 1-3, proximal leaflike, becoming linear-lanceolate, less hairy and more stipitate-glandular distally, larger bracts subtending heads absent or very rare. Involucres cylindric to campanulo-hemispheric, 7-9(-10.5) mm. Phyllaries in 4-5 series, outer and mid narrowly triangular, unequal, margins hyaline, fimbriate-ciliate apically, faces sparsely strigose, eglandular or sparsely to moderately stipitate-glandular. Ray florets 16-29(-38); laminae 10.5-17(-21.5) × 1-2(-2.6) mm. Disc florets (23-)32-66; corolla barely ampliate, 5-6.6 mm, glabrous, lobes 0.5-1 mm, glabrous or glabrate. Cypselae monomorphic, compressed obconic, 1.7-3.9 mm, ribs 7-10 (often brownish), faces moderately strigose; pappi off-white, outer of linear scales 0.2-1 mm, inner of bristles 5-7 mm, longest weakly clavate. Chance introductions (usually emphemeral) of Heterotheca camporum have occurred in Michigan, New Jersey, and likely other eastern states. Heterotheca camporum has well-developed serrations along the margins of its distal cauline leaves, which no other species has, although basal leaves in some species may have one or two serrations distally.