FOREST TREES OF THE PACIFIC SLOPE. 199 



strips, and the tips of the strips are split in two. The stems of the leaves 

 are armed on their two edges with irregular, straight or curved, sharp teeth. 

 New leaves appear each year from the summit of the trunk As those of the 

 previous year die, they bend down, forming a dense thatch-like mass about the 

 trunk (fig. 77). This adheres 1<» the trunk for many years, finally falling and 

 leaving the torn, wide overlapping bases of the leaves covering the trunk. Later 

 diameter growth loosens these, and the trunk then becomes smooth, its rind 

 (bark-like) being seamed and ridged somewhat as ordinary trees are. 



The minute white flowers are perfect (male and female organs present in 

 each) and borne in large branched clusters. The small, berry-like, elliptical 

 fruit is black, with one russet-brown seed. 



Only two species of these palms are known, and but one is found within the 

 United States. This inhabits desert parts of southern California and extends 

 into Lower California. The other species grows in Mexico and in the southern 

 part of Lower California. 



Commercially, these trees are of little importance (the trunks do not afford 



stable wood), except for ornamental purposes, for which they are much planted. 



They deserve protection and extension, however, since they are capable of 



forming true forest cover in desert localities where very few other trees grow 



naturally. 



Washington Palm. 



Neowashingtoiiin filifera" iWendl.) Sudworth. 



DISTINGUISHING CHARACTERISTICS. 



Washington palm is known also as " desert palm " and " fan palm." It is 

 the largest of our indigenous palms, growing to a height of from 35 to 50 or 

 sometimes GO to 70 feet, with a diameter of from 20 to 30 inches. The 

 trunks taper very gradually, and sometimes appear to be of almost the same 

 diameter throughout. As a rule they are more or less bent. The bark-like rind, 

 marked by narrow seams, is pale cinnamon to dull reddish brown. A broad open 

 crown of about 50 huge, fan-like, pale green leaves caps the trunk (fig. 77). If 

 lire has not destroyed them, the drooping dead leaves of many years' growth 

 form a dense thatch-like shroud about the trunk down to within a few feet of 

 the ground. When the lower dead leaves have been burned off there is a mass 

 of dead leaves just beneath the green head (fig. 77). Very many of these 

 curious trunks are marked by tire, to which they are particularly subject until 

 their covering of dry leaves is consumed. A remarkable resistant power ap- 

 parently enables most of the trees to endure such burnings without injury, for 

 they grow on thriftily afterwards. 



The great leaves (fig. 78, &), about 4* feet broad and somewhat longer, have 

 stems 5 or G feet long, armed on their two edges with irregular, sharp, straight 

 or hooked teeth (fig. 78, a). They are deeply slashed into stiff ribbon-like divi- 

 sions (2-cleft at the ends), the edges of which are frayed into many long, 

 thread-like fibers (tig. 78, b). The minute white flowers, produced every year 

 when a tree begins to bloom, are borne in large branched clusters from 8 to 10 

 feet long in the crown of green leaves. At the base the flower stems and 

 branches are noticeably flattened, forming two edges; elsewhere they are 

 rounded. 



« Since this bulletin went to press Dr. S. B. Parish has published (Bot. Gaz. 44 : 408- 

 4.'>4. litoTi a most valuable contribution to our meager knowledge of the Washington 

 palm. He points out that there is grave doubt as to what the plant originally described 

 (by Wendland) as our Washington palm really is. and distinguishes the following 

 species and varieties: Washingtonia filifera, W. filifera robuata, W. filifera microepertnoi 

 W. gracilis, W. s'onorm. Dr. Parish's 11*. filifera rohusta corresponds with the palm 

 described here as N. filifera. 



