From Wikipedia, the free encyclopedia

Washingtonia
Washingtonia filifera near Twentynine Palms, California
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Liliopsida Order: Arecales Family: Arecaceae Genus: Washingtonia Raf.
Species
Washingtonia filifera Washingtonia robusta

Washingtonia is a genus of palms, native to the southwestern United States (in southern California, southwest Arizona) and northwest Mexico (in northern Baja California and Sonora).

They are fan palms (Arecaceae tribe Corypheae), with the leaves with a bare petiole terminating in a rounded fan of numerous leaflets. The flowers are in a dense inflorescence, with the fruits maturing into a small blackish-brown drupe 6-10 mm diameter with a thin layer of sweet flesh over the single seed.

There are two species:

• Washingtonia filifera (Lindl. ex André) H.Wendl. California Washingtonia, Northern Washingtonia, California fan palm, or Desert fan palm. Tree to 23 m tall; leaves large, with petiole up to 2 m long, and leaflets up to 2 m long. Inflorescence to 5 m long; flowers white; fruit oval. Southwestern USA, just into extreme northwest Mexico.
• Washingtonia robusta H.Wendl. Mexican Washingtonia or Southern Washingtonia. Tree to 25 m tall; leaves smaller, with petiole up to 1 m long, and leaflets up to 1 m long. Inflorescence to 3 m long; flowers pale orange-pink; fruit spherical. Northwest Mexico.

Washingtonia Palms near Twentynine Palms, California, USA.

The fruit is edible, and was used by Native American people as a minor food source. They are also eaten by birds, which disperse the seeds in their droppings after digesting the fruit pulp. Washingtonia species are also used as food plants by the larvae of some Lepidoptera species including Paysandisia archon.

Both species are cultivated as ornamental trees, widely planted in California in particular, but also in extreme southwest Utah and the Mediterranean region in southern Europe, and parts of Australia. The species is also attempted, rather unsuccessfully, in cooler climates such as western Oregon and Washington, the Columbia Basin, and the milder parts of the southern British Isles. W. filifera is actually very hardy in a dry climate and able to survive brief temperatures in the vicinity of -15C (5F) provided the air and soil are not too wet and the afternoon temperatures are not too cold. Intolerance of wet, prolonged cold is the main reason the filifera species cannot grow properly in temperate marine climates. W. robusta is less sensitive to moisture than filifera, but far tenderer to cold.

The genus is named after George Washington.

• Flora of North America: Washingtonia