Oenothera biennis, common evening primrose, produces seeds that have a high oil content containing gamma-linolenic acid (GLA), a fatty acid of medicinal, and dietary importance. These plants are commonly found in sandy or gravelly soils and have the ability to tolerate hot, dry conditions. Plants containing economically important oils such as GLA are potential crops for arid environments with minimal irrigation. Many native species of evening primrose have not yet been evaluated for oil content. In this project, a systematic survey of native Onagraceae species was conducted in the Texas Panhandle and the Texas South Plains. Six species of Oenothera and two species of Calylophus were found. Locations were recorded with a Global Positioning System (GPS) to facilitate relocation and collection. Distribution maps were made for each species. The occurrence of species varied greatly from north to south, with the exception of one species that occurred throughout the area surveyed. Seeds were collected from each species and from various locations within the range of each species. Germination percentages were determined for each species and had a wide variation. Evaluation of the oil content of this native germplasm could possibly lead to development of new commercial sources of GLA.