Helianthus debilis is a species of sunflower known by the common names cucumberleaf sunflower, beach sunflower, weak sunflower, and East Coast dune sunflower. It is native to the United States, where it can be found along the Atlantic and Gulf Coasts. It is known elsewhere as an introduced species, such as South Africa, Australia, Taiwan, Slovakia, and Cuba. There are several subspecies. At one point there were eight. Five are currently recognized.