possibly not the right one - purpleleaf willow-herb
Epilobium canum found in Eaton Canyon
San Diego County, California, US
common along the road
Large four petalled yellow flower. Grew on stalks reaching up to 3 meters high.
Onagraceae, known as the willowherb family or evening primrose family, is a family of flowering plants. It includes approximately 650 species in 17 genera. They are herbs, shrubs, and trees. The family is widespread, occurring on every continent from boreal to tropical regions.