1917] BRUSH—SYCAMORE WOODS 493 
than the average wood fiber. They have numerous oval oblique 
bordered pits. 
Pith rays (pls. XXXII, XXXV, XXXVIII, pr).—These are 
very conspicuous. They are on the average 14 cells (0.29 mm.) in 
width and are about 5 times as high. The pith ray cells are ellip- 
tical in the tangential section and are usually much elongated 
radially. The side walls are thickened and marked by many 
dotlike slightly bordered pits which place them in communication 
with the surrounding elements (fig. 3, bp). Crystals are very 
abundant in the pith ray cells. : 
P. Wrighttt S. Wats., Arizona sycamore 
(pls. XXXII, XXXVI) 
_ Distribution —Southwestern New Mexico and southern Arizona, 
Mexico (Sonora). 
Uses.—The wood of Arizona sycamore is little used. This is 
on account of its small dimensions and the limited supply of suitable 
saw logs. It is very similar in its chief structural characters to the 
wood of California sycamore. While this wood does not occur in 
the market, it possesses qualities useful for the same purposes as 
the wood of the common sycamore, and it could be applied to 
these uses were the tree larger and sufficiently abundant to warrant 
its exploitation. 
Gross characters.—The wood is somewhat lighter and softer and 
also less cross-grained and easier to split than that of the com- 
mon sycamore. It is weak, very close-grained, and quite tough, 
but not very durable in contact with the soil. The sapwood is 
light colored or almost white, and the heartwood is light brown 
with a reddish tinge. The annual rings (pl. XXXIII) are 
clearly defined on a smooth transverse section. The pith rays 
are clearly visible, though not as prominent as those of the com- 
mon sycamore. 
Minute characters —Vessels in transverse section (pl. XX XIII, v) 
are arranged singly or in groups, just as in the common sycamore 
already described. In the beginning of the early wood the vessels 
