Vessels . --Vessels are relatively fev, rather large, and frequently blocked by 
deposits of yellovish-vhite siliceous material. They are fairly evenly distri- 
buted, sometimes in radial groups (5). 
Rays.--Ravs are not readily visible on cross sections without magnification 
T5T9). 
Parenchyma . - -Parenchyma in tangential bands is abundant and has been used by some 
to differentiate species or varieties (5, 9; 36) • 
Report No. R1913 -6- 
