Where the Mediterranean climate of the California Floristic Province collides with the subtropical Sonoran Desert near El Rosario, hybrids with two other species of cacti are found.
It is the sole member of the monotypic genus Bergerocactus, named after German botanist Alwin Berger.
The stems are usually less than 2 metres (6.6 ft) long, covered in numerous, interlaced, yellow and needle-like spines.
After blooming, a reddish, globular fruit emerges, covered in dense spines, and extruding seeds and pulp at the tip.
[5] Its generic name comes from those of its parents (Mytillocactus and Bergerocactus) and its specific epithet, "lindsayi", is in honor of the botanist George Lindsay.
The populations remaining in San Diego are disjunct, located in Border Field State Park, Torrey Pines State Park, and Cabrillo National Monument, as the urban development in San Diego has relegated many species to these protected areas.
On San Clemente Island, the golden cactus is found inhabiting rocky canyon walls.
[12] In Baja California, the species continues from the border south into the succulent scrub to El Rosario.
[4] It occurs on numerous islands off the coast; however, climate change and other anthropogenic influences are threatening the insular populations.