The genus Helianthus is composed of 51 species (14 annual and 37 perennial), all native to North America. Several wild sunflower species are rare, threatened, or endangered due to their restricted distribution and the encroachment of human activities destroying their habitats. The objective of this research was to collect achenes from as many populations as possible of Helianthus californicus (California sunflower), H. eggertii (Eggert's sunflower), H. schweinitzii (Schweinitz's sunflower), H. verticillatus ( whorled sunflower), H. smithii (Smith's sunflower) and H. porteri, formerly Viguiera porteri, (Porter's sunflower) to conserve them and make them available for future improvement of cultivated sunflower. The first exploration, for perennial California sunflower, took place September 2003, covering 2660 miles over 10 days in central and southern California where 12 populations were collected. The second exploration, for Eggert's, Schweinitz's, whorled, Smith's and Porter's sunflower, was undertaken in October 2003. It covered 2865 miles over 12 days in the states of Georgia, Tennessee, North and South Carolina, and Alabama. Thirteen populations of Eggert's sunflower, a federally threatened perennial species currently being considered for delisting by the US Fish and Wildlife Service, and 14 populations of Schweinitz's sunflower, a federally endangered endemic perennial sunflower from the Piedmont of North and South Carolina were collected. Two populations of the perennial whorled sunflower, a recently rediscovered species described over 100 years ago in Tennessee were collected. This species is currently being considered as a “candidate species” for protection. Additionally, eight populations of annual Porter's sunflower and one population of perennial Smith's sunflower were collected. The collection of populations of these species will ensure the future preservation of these rare and endangered species. It will also allow sunflower researchers globally the opportunity to investigate these wild species for their potential contribution of useful traits for the improvement of cultivated sunflower.