Evening Primrose: Night Willow-herb.
Oenothera biennis. Evening Primrose Family. June - Sept.
A plant 1 - 5 feet high, found in fields and roadsides. Labrador to Gulf, west to Rockies.
Yellow, 4-parted, 1 - 2 inches across, in terminal spikes, opening in the evening.
Alternate, lance-shaped, mostly seated on stem, obscurely toothed. Plant stem leafy, hairy, more or less branched.
Common Evening Primrose.