38 BULLETIN 816, U. S. DEPARTMENT OF AGRICULTURE. 
from the region of San Jose del Cabo, the extremity of Lower Cali- 
fornia, in the early days of travel. The name robusta alludes to the | 
fact that this species grows much more rapidly in height than | 
W. fiifera, though- the trunk is more slender. Both species are — | 
__ hardy and thrive well through regions 2,3, and 5, and also im regions | 
(12 and 13. Washingtonia robusta requires less heat than W. fillifera, 
but both will endure several degrees of frost. Even in California 
Washingtonia robusta is distinctly preferable for localities near the 
coast. In the vicinity of San Diego the leaves of Washingtonia filifera 
become badly infested with a parasitic fungus that does not attack 
Washingtoma robusta. 
OTHER HARDY FAN PALMS. 
The species most commonly used for street and ornamental plant- 
ing in the California coast districts is the Chinese or windmill palm.! 
This palm has a slender trunk clothed with brown fibers, flat fan- 
shaped leaves, and rather straight radiating segments. The same 
species is hardy at New Orleans and Charleston, and even at Laurens, 
S. C., at an altitude of 600 feet, but it does not thrive in the sandy 
soil of Florida. 
The vegetable hair palm,? a native of Spain, Sicily, and North 
Africa, is similar to the Chinese palm but smaller and more compact 
and with large,sharp spines on the petioles of the leaves. When 
young it suckers from the base, like the date palm, so that clusters of 
it may be formed. 
The Guadeloupe Island palm* is one of the most popular species 
in southern California in the region of Santa Barbara, Los Angeles, 
and San Diego. This palm is a native of Guadeloupe Island, off 
the coast of lower California, and is not known to occur elsewhere in 
the wild state. It is well adapted to the cool coast climate of Cali- 
fornia, but not to the interior valleys. It is smaller than the Wash- 
ingtonia palms, with a rather short trunk, 15 to 20 feet high, and a 
dense crown of fresh green leaves. 
The California blue palm,* formerly placed in the same genus with 
the Guadeloupe Island species, is very distinct in habits as well as in 
general appearance, having bluish or grayish green leaves, strongly 
toothed petioles, and long, slender inflorescences. The trunk is 
very robust, often 2 to 3 feet in diameter, and is said to attain a 
height of 30 to 40 feet in Mexico. Several of these features are shared 
with the Washingtonia palms. It also has the ability to grow in the 
dry, hot interior valleys (regions 3 and 5). In Texas the blue palm 
has proved hardy at San Antonio, and even as far north as Austin. 
1 Trachycarpus ercelsa (Thunb.) Wendl. 
2 Chamaerops humilis L. 
3 Erythea edulis (H. Wendl.) S. Wats. 
4 Glaucothea armata (formerly known as Erythea armata). See Cook, O. F., Glaucothea, a new genus of 
palms from Lower California. Jn Jour. Washington Acad. Sci., v. 5, p. 236-241. 1915. 
