Palm Primer for the San Gabriel Mountains

There is one palm native to California, Washingtonia filifera, California fan palm. Washingtonia robusta, Mexican fan palm, aka the sky duster, is widely planted here and seems to be more widespread.

There are two types of leaves on the most common palm trees, fans or feathers. Washingtonias are fan palms, that is, all the leaf segments begin from one point, not several along a central stem like the other kind, the feather palm of which the date and coconut palms are commonly recognized examples.

palm leaves

Description: tall, columnar, unbranched tree with a topknot of fresh leaves and often of skirt of turned-down dead ones

How to distinguish between the California and the Mexican fan palm

Leaf Colorgray-greenyellow-green
Leaf Margintattered fiberssmooth
Leak Stalkgreenred streak on underside
Trunk Widthstoutslender
Trunk Basenot swollenswollen

Habitat: California fan palms are often found growing along the San Andreas fault line and by seeps, springs and streams, in canyons, and in desert washes where water is available. They mark desert oases. They are hardy to 18° F and found generally below 3500 feet.

The Jepson Manual does not recognize the robusta species as having naturalized, but it is often found, growing in gutters, outfalls, debris basins, lawns and freeway verges, any place where waste water collects, even along road cuts as in the above picture taken near Blue Cut on I-15 on the San Andreas Fault.

Locations: By names on the land: Palm Springs, Palm Desert, Twenty-nine Palms, Thousand Palms, Dos Palmas Spring, Palm Wash, Four Palms Spring, Seventeen Palms Oasis, Seven Palms Valley. Numbers and water sources often seem to be connected to the name. True distribution of palms is probably not documented because of the difficulty of collecting and preserving the frond according to the Sierra Club site listed above!

Go to Keys to Identifying Selected Plant Groups in the SGM

Copyright © 2002 by Jane Strong and Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to us at this source:
Comments and feedback: Jane Strong | Tom Chester
Updated 21 December 2002.