P.H.Raven Oenothera serrulata is a species of flowering plant in the Onagraceae known by the common name yellow sundrops.

[3] This plant is a subshrub that branches and forms a bushy clump up to 46 centimetres (18 inches) tall.

The yellow flowers bloom between March and November and have four petals.

[4] This drought- and heat-tolerant species grows in many types of substrate, including caliche, limestone, and gypsum.

[1] The leaves turn so that their edges face the sun, an adaptation to hot conditions.