Plant Highlight: Washingtonia filifera
Among the palms planted at the Ruth Bancroft Garden is a trio of Washingtonia filifera, the California Fan Palm. This is the only palm native to California, and it occurs in Arizona, southern Nevada and northern Baja California as well. Although it grows in desert areas, it is invariably found near springs or water courses, where the roots have access to water.
The California Fan Palm is closely related to the Mexican Fan Palm, Washingtonia robusta, which is the species commonly planted along streets in Los Angeles and other warmer parts of California. However, Washingtonia filifera differs in being a stouter-trunked tree with somewhat larger leaves and longer drooping threads at the tips of the leaves. It is also more cold-tolerant than its slimmer cousin.
As with many kinds of palms, the leaf-stalk of Washingtonia filifera is very tough and edged with sharp teeth. As the leaves wither and die they do not drop off. Instead, they droop down and form a brownish-gray ”skirt” below the crown of the tree. These old leaves are sometimes removed, but at the Ruth Bancroft Garden we prefer to leave them in order to keep the natural look of the trees.
In habitat, Washingtonia filifera normally flowers in spring, but in cultivation it may do so later, as is the case with our palm coming into bloom in September-October. The inflorescence is nearly the length of the leaves, with numerous slender pendulous branches bearing small white flowers. The fruit is a small purplish-black drupe, which was important as a food source for Native Americans in the region where it occurs.