Washingtonia filifera var. robusta, commonly known as the Mexican fan palm, Mexican washingtonia, or skyduster, is a flowering plant in the family Arecaceae native to the Sonoran desert along the Baja California peninsula. Despite its limited native distribution, W. filifera var. robusta is one of the most widely cultivated subtropical palms in the world. It is naturalized across the southern United States, Mediterranean, and Middle East.
Description
Washingtonia filifera var. robusta grows to 25 m (82 ft) tall, rarely up to 30 m (98 ft). The leaves have a petiole up to 1 m (3 ft 3 in) long, and a palmate fan of leaflets up to 1 m (3 ft 3 in) long. The petioles are armed with sharp thorns. The inflorescence is up to 3 m (10 ft) long, with numerous small, pale orange-pink flowers. The fruit is a spherical, blue-black drupe,
W. filifera var. filifera—which occupies a more northerly distribution in the states of Arizona, Baja California, and California—is often confused with W. f. var. robusta for their overall similar appearance.
Taxonomy
The Plants of the World Online (POWO), curated by the Royal Botanic Gardens, Kew, currently recognizes the Mexican fan palm as a variety of Washingtonia filifera, along with two other infraspecifics. Under this classification, the Mexican fan palm corresponds specifically to Washingtonia filifera var. robusta.
Washingtonia filifera var. filifera
Washingtonia filifera var. robusta (H.Wendl.) Parish
Washingtonia filifera var. sonorae (S.Watson) M. E. Jones
This classification has been adopted by major global taxonomic databases such as Plants of the World Online and World Flora Online, though some horticultural and regional authorities continue to recognize the palm as the distinct species, Washingtonia robusta.
