About Oenothera serrulata Nutt.
Oenothera serrulata Nutt. is a flowering plant species in the family Onagraceae. Its most common name is yellow sundrops, and it also goes by the additional common names halfshrub sundrop, serrate-leaved evening primrose, shrubby evening primrose, plains yellow primrose, and halfleaf sundrop. It is native to central North America, specifically central Canada and the central United States. This species is a branching subshrub that forms bushy clumps reaching up to 46 centimeters (18 inches) in height. Its toothed leaves can grow up to 8.9 centimeters (3.5 inches) long. Yellow four-petaled flowers bloom from March to November. The flowers open in the morning and close in the afternoon, and fade to orange or pink as they age. The plant produces a cylindrical capsule as its fruit. It grows in dry open plains and prairies. This species tolerates drought and heat, and can grow in many types of growing substrate, including caliche, limestone, and gypsum. As an adaptation to hot conditions, its leaves turn to position their edges toward the sun.
