Sundrops, Small
 

Oenothera perennis
An erect 1-2' plant with a simple, finely hairy, brownish stem. The alternate leaves are smooth-edged. The lower leaves are paddle-shaped, the upper are lance-shaped or linear. The 1/2-1" flowers are in a terminal spike and bloom during the day. The 4 yellow petals are nearly round and have a small notch at the tip. The sepals are sweptback. The stamens are furry, the stigma globular and lumpy, and the capsules are club-shaped. Blooms June-August in grassy fields, roadsides.

Sundrops (O. fruticosa) has larger flowers that have smooth rather than furry stamens.