Evening Primrose or Sundrops are Oenothera
The wildflower Evening Primrose, Oenothera macrocarpa is also called Ozark Sundrops. The Great Plains Nature Center site says that pollination is provided by large hawkmoths and possibly hummingbirds. The flowers have a distinctive, large X-shaped pistil which projects beyond the stamens. GPNC site also says Evening Primrose is a complex of four similar subspecies which occur in the southern half of the Great Plains. 1. Fremont's Evening Primrose (subsp. fremontii) - found in chalk badlands and rocky hillsides in northwest and north central Kansas and four counties in Nebraska. Formerly considered a separate species, it has smaller flowers and shorter wings on its seed pods than the other three. 2. Hoary Evening Primrose (subsp. incana) - found from southwestern Kansas to the Oklahoma and Texas panhandles. Hoary Evening Primrose is densely covered with short hairs. 3. Oklahoma Evening Primrose (subsp. oklahomensis) - found from the Gyp Hills of south central Kansas south into Texa...