This rhizomatous diploid (2n = 20) is widespread on damp soils in eastern states except those adjacent to Canada. In Ky. it is locally abundant in pastures with infrequent mowing. The segregated genus Conoclinum is distinct from Fleischmannia and Eupatorium and Ageratina in its conic receptacles (versus flat or convex), but it often resembles Fleischmannia in its blue or purplish flowers (FNA 21). Within eastern North America, C. coelestinum is distinguished further by its plain blue flowers, with ca. 35-70 per head, its triangular to deltate or ovate leaves with ca. 0.5-2 cm petioles, and its strongly rhizomatous habit.