This poppy is native to San Diego, Ventura, and Santa Barbara counties in California, as well as Baja California, Mexico, where it grows in dry canyons in chaparral and coastal sage scrub plant communities.

[2] Like its relative Romneya coulteri, it is used as an ornamental plant, kept for its large, showy flowers.

The inflorescence is a large, solitary flower with six white petals each 4–8 centimetres (1.6–3.1 in) long.

In the past the two species were placed in synonymy, but they are currently regarded as distinct by California botanists.

It is named after Irish astronomer John Thomas Romney Robinson.