Washingtonia

taxobox
name = "Washingtonia"

---

image_caption = "Washingtonia filifera" near Twentynine Palms, California
regnum = Plantae
unranked_divisio = Angiosperms
unranked_classis = Monocots
unranked_ordo = Commelinids
ordo = Arecales
familia = Arecaceae
subfamilia = Coryphoideae
tribus = Corypheae
genus = "Washingtonia"
genus_authority = H. Wendl.H.A. Wendland, Botanische Zeitung 37:1xi, 68, 148. 1879 (conserved name)]
subdivision_ranks = Species
subdivision = *"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). Both "Washingtonia" species are commonly cultivated across the United States, the Middle East, and southern Europe e.g Croatia, where they have greatly hybridized.

They are fan palms (Corypheae tribe), 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.Riffle, Robert L. and Craft, Paul (2003) "An Encyclopedia of Cultivated Palms". Portland: Timber Press. ISBN-10: 0881925586 / ISBN-13: 978-0881925586]

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.

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, the Mediterranean region in southern Europe like Croatia, parts of Australia and the leeward sides of the Hawaiian Islands. 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 -15 °C (5 °F) 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 more easily damaged by cold.

The genus is named after George Washington.

References

reflist

External links

* [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=134783 Flora of North America: "Washingtonia"]
* [http://www.scanpalm.no/washingtonia_english.html Scanpalm: "Washingtonia"]