Oenothera fruticosa

Oenothera fruticosa, narrowleaf evening primrose or narrow-leaved sundrops, is a species of flowering plant in the evening primrose genus of the family Onagraceae, native to much of eastern North America. It is an erect herbaceous perennial growing to 20–90 cm (8–35 in) tall, with alternative, simple, entire or slightly toothed leaves. The saucer- or cup-shaped yellow flowers, 2.5–5 cm (1–2 in) in diameter, appear in late spring and summer. The fruit is a capsule that is strongly 4-angled or winged and shaped like a club.