Opuntia treleasei

Opuntia treleasei (basilaris ssp. treleasei) is possibly the only or one of the two cactus endemics of California. In literature it is also reported from Arizona, but not recently confirmed. It is also known as 'Bakersfield cactus', as it grows - or used to - right where town of Bakersfield spreads. Habitat destruction makes it threatened species, though it is very resilient, and also found in couple state preserves South of the town, and up in the hills along Kern river.
Opuntia treleasei does not really remind of O.basilaris in its appearance, forming wide-spreading low-growing bushes. It is also spiny. Pads are bluish like with O.basilaris, and flowers are pink.
In habitat this plant grows mainly on sand, in lower elevations of Sierra Western foothills. It is moderately frost hardy, and wet winters are just the way it is at home. For successful blooming early watering is essential, otherwise it is an easy in culture plant, probably better suited for in-the-ground growing due to the size. It is a slow growing Opuntia, but faster than O.basilaris and in culture will overgrow any reasonable sized pot in not that many years.