
California fan palm is the only palm that is actually native to remote regions of California. However, Mexican fan palm, Washingtonia robusta, is much more common. Technically, its native range is not far away. It had been the most popular of palms prior to the 1990s. It is more adaptable to more populous climates. Also, it naturalizes within some regions.
Mexican fan palms grow vigorously while young. Growth decelerates with maturity. Very old trees can grow very slowly without completely stagnating. Wild specimens may have potential to survive for a few centuries with such slow growth. Cultivation and irrigation of home gardens may limit this potential. Few local specimens are more than a century old.
Mexican fan palms are taller and slimmer than California fan palms. Their trunks lean as prevailing wind blows them. They easily grow fifty feet tall, and eventually get a hundred feet tall. Such tall and leaning trunks can suspend their canopies over adjacent gardens. Their pleated and palmate leaves are about three feet wide, on petioles with nasty teeth.