﻿AN ECONOMIC STUDY OP ACACIAS. 27 



ground, 2 feet 8 inches. At Niles, a tree 46 years old, on side valley 

 soil, 76 feet above San Francisco Bay, top broken off at height of 

 65 feet, though the tree had been about 80 feet high, diameter 2 feet 

 6 inches. Near Alvarado, a tree 45 years old, on rich soil, 85 feet 

 high, diameter, breast high, 3 feet 9 inches. 



All portions of the Sacramento and San Joaquin Valleys appear 

 well adapted to the growth of Acacia melanoxylon. At the Chico 

 forestry station and elsewhere it showed no injury, except to the 

 young tips of the top branches, during the low temperature of the 

 coldest seasons between 1890 and 1913 (16°, 14°, and 12°). Large 

 eucalypts were killed to the ground by these frosts. 



The bark of this species yields about 11 per cent of tannic acid, 

 which could be utilized profitably when the timber is cut by con- 

 centrating it in the form of an extract. The inner bark, as with 

 some other acacias, yields a valuable bast or fiber material. 



Acacia decurrens group. — There is little difference in the woods of 

 the three leading varieties of the Acacia decurrens group (normalis, 

 mollis, and dealbata), but the last two grow more rapidly and attain 

 the larger size. Dealbata trees have been measured and found to be 

 100 feet high and 4 feet in stem diameter. This variety has been 

 naturalized in southern India since 1840 and extended over a large 

 area. The timber of all three varieties is moderately hard, light 

 brown in color, easily worked, and strong; it is used by coopers and 

 house builders; it is valuable for posts, for rustic work, for mine 

 props under ground, and for fuel. Its weight is about 47 pounds to 

 the cubic foot. 







Acacia decurrens normalis and mollis are more generally planted 

 than dealbata. Von Mueller gives the weight of their timber at from 

 45 to 48 pounds per cubic foot. Maiden reports that three slabs of 

 normalis at the Technological Museum, seasoned for more than 

 25 years, weighed, respectively, 52, 53, and nearly 63 pounds per cubic 

 foot. 



Other timber species. — Many other species of acacia yield valuable 

 timber. Of those listed, all have been grown in California. 



Acacia acuminata. — Stem diameter, 12 inches. Wood strong and 

 very hard, red-brown in color, and durable. Has a raspberry-like 

 scent. 



Acacia aneura. — Stem diameter, 10 to 12 inches. Exceedingly 

 hard and strong wood of a dark-brown color. 



Acacia arabica. — Stem diameter of 2 feet. Wood used for boats, 

 water wheels, and many implements, on account of its strength and 

 durability. The tanbark is a by-product of this species. (See pi. II.) 



Acacia armata. — Shrub or small tree. Wood beautifully grained 

 and durable. 



