Washingtonia filifera (Linden) Wendl., Arecaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 11.5 (Go to the risk assessment)

Common name(s): [more details]

English: California fan palm, California washingtonia, cotton palm, desert fan palm, northern fan palm, petticoat palm, Washington palm

French: palmier évantail de Californie

Habit:  tree

Description:  "Sex: Hermaphrodite.  Trunk: To 50 ft. fall; thick, to 3 ft. diameter; not enlarged at base; upper part, or sometimes all the trunk, covered with a huge shag or petticoat of dead leaves.  If leaves are cut off, the leafbases form a covering for the trunk, compact, but with no regular pattern.  The gray surface of trunk, if exposed, is marked with vertical chinks or ridges that are more prominent than the rings.  Petiole: Long, to 6 ft.; 6 in. broad near base; margins armed with prominent teeth; green in color; leafbases are sometimes brown or reddish.  Leaf: To 6 ft. or more across; divided more than halfway to base; many long threads attached to segments and sinuses throughout life of tree.  Segments: 50 or more gray-green; not glaucous.  Flowerstalk: From lower leaves; 9-12 ft. long; erect at first, then hanging with fruit, and eventually becoming involved in the shag of dead leaves, of which it becomes a part.  Flowers: Small; numerous; white.  Fruit: 1/3 in. long, 1/4 in. broad; ovoid; lightly wrinkled.  Seed: Single; same shape as fruit, but trifle smaller" (McCarrach, 1960; p. 264).

Habitat/ecology:  "Groves, moist places, seeps, springs, stream sides; to 1200 m" (Hickman, 1993; p. 1105). Adaptable to a wide range of soils and climates. Can grow in extreme alkaline soils that have a pH as high as 9.2.  Considered very disease and pest resistant and quite resistant to lethal yellowing disease. Prefers exposure to full sun but also grows well in part sun/shade. Drought tolerant and can withstand frosts and freezes as well as extreme heat (Floridata).

Propagation:  Seed

Native range:  "Southern California, western Arizona, northwestern Mexico" (McCarrach, 1960; p. 264).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 89)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank L./Bartlett, Randal T. (2002) (p. 3) West Maui. Voucher cited: Oppenheimer H30016 (BISH)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)
United States (west coast) United States (west coast states)	USA (California)	native	U.S. Dept. Agr., Agr. Res. Serv. (2009)

Additional information:
Report (PDF format) from US Geological Survey, Biological Resources Division, Haleakala Field Station, Hawaii "Plants of Hawaii".
Fact sheet from Floridata.

Additional online information about Washingtonia filifera is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Washingtonia filifera as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Washingtonia filifera may be available from the Germplasm Resources Information Network (GRIN).

References:

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1987. A geographical checklist of the Micronesian monocotyledonae. Micronesica 20:1-126.

Hickman, J. C. 1993. The Jepson manual: higher plants of California. U. Cal. Press, Berkeley. 1400 pp.

McCurrach, J. C. 1960. Palms of the world. Harper, New York.

Oppenheimer, Hank L./Bartlett, Randal T. 2002. New plant records from the main Hawaiian Islands. In: Evenhuis, Neal L. and Eldredge, Lucius G., eds. Records of the Hawaii Biological Survey for 2000. Part 2: Notes. Bishop Museum Occasional Papers. 69:1-14.

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.