This native of southern and Baja California, is a true member of the Papaveraceae or poppy family. Indigenous to the dry canyon washes of chaparral country, one may encounter native stands in Orange, Riverside and San Diego counties and into the Baja Peninsula of Mexico. Typically the plant is found in sandy, well-drained soils with minimal organic matter. Romneya may be easily cultivated in other locations if similar conditions are provided. Matalija poppy has a solitary, fragrant flower that may reach 6 to 9 inches in diameter.
Solitary flowers located at the ends of branches somewhat resemble a peony.
The corolla is comprised of six identical petals that appear to be made of crinkled white paper. Within the center is a large cluster of bright yellow stamens surrounded by a light green pistil. The flowers will remain open for several days. Flowering occurs from spring into early summer prior to the long hot season, with an occasional bloom found in the fall. The flowers fade to leave a large capsule that contains numerous dark seeds.