Oenothera fruticosa
A fine-haired 1-3' plant, sometimes with a reddish stem. The alternate leaves are not toothed but are somewhat wavy-edged. The stalked lower leaves are lance-shaped or oval; the sessile upper leaves are narrower. The buds are upright and the 1-1 3/4" flowers are in terminal clusters and bloom during the day. The 4 yellow petals are broad and notched. The calyx is lighter yellow, and there are 8 bright yellow anthers and a 4-part stigma. The 3/8" seed capsule is club-shaped. Blooms May-September in meadows, fields, roadsides.

The similar Small sundrops (O. perennis) has a smaller flower with furry stamens and a lumpy, globular stigma.