Heterotheca subaxillaris (J. de Lamarck) N. Britton & H. Rusby is a New World aromatic, pioneer species that rapidly colonizes disturbed, xeric habitats on temperate and subtropical coastal dunes. Also known as camphorweed, H. subaxillaris has low moisture requirements, and it tolerates low nutrient levels and high sand temperatures. Dimorphic achenes have a dual germination strategy. Disc achenes are nondormant, and seeds germinate over a wide range of temperature conditions, whereas ray achenes are dormant at maturity and require after-ripening before seed germination. Heterotheca subaxillaris competes well with other species in disturbed sites, but growth and reproduction are inhibited when it is in competition with dominant dune grasses.