Erythranthe diffusa, also known as Palomar monkeyflower, is a species of plant native to North America.[1] This plant is endemic to the Californias, and is considered a rare plant due to its limited range. E. diffusa grows up to 8inches in height, and produces purple, pink, and yellow flowers.[2] It prefers to grow in gravelly or sandy soil in chaparral or a low-elevation coniferous habitat.[3] E. diffusa has been observed in Los Angeles County, Orange County, Riverside County, San Diego County, Santa Clara County, and Baja California. The Palomar monkeyflower is threatened by recreational activities and real estate development of its preferred wild habitat.