Sand primrose Oenothera rhombipetala Nutt. ex T. & G. Oenothera clelandii D. Dietr. & Raven
Notes: Oenothera rhombipetala is shorter than O. villosa (2’ to 3’ tall). The leaves are 2” by 1/2” or smaller. The flowers are smaller, and the petals are 1/2”’long and are rhomboid-shaped. Fruits are 1/2”’long. Flowering is from early July to late September, and fruiting begins in mid-July. O. rhombipetala is frequent in sandy soils on prairies and in open places.