High Plains Yellow Sundrops, Calylophus hartwegii | High Country Gardens

Oenothera hartwegii BenthFamily: OnagraceaeSynonyms: Calylophus hartwegii Common names: Hartweg’s sundrops, Evening primrose, Sun cupHartweg’s sundrops is a perennial, upright, bushy plant that forms a gently rounded shape, usually 30 to 45 cm. tall and 60 cm. wide. It is native to the desert Southwest of the United States and to the Northern and Western Mexico. LEAVES: green and narrow FLOWERS: soft 4 petaled yellow cup-shaped flowers ( 2 inches wide ) that open during daylight and close at nig