﻿22 BULLETIN 9, U. S. DEPARTMENT OF AGRICULTURE. 



Prof. Jared C. Smith has made a full and careful report of experi- 

 ments with black wattles in Hawaii. 1 In this he states that acacias 

 have been grown in the Hawaiian Islands for about 40 years, thriving 

 on heavy soils with a rainfall of from 80 to 150 inches. The remark- 

 able fact in connection with this exceedingly heavy rainfall is the 

 adaptability of the acacias to A r arious conditions from drought to 

 deluge, and points to their possible use in such locations as the 

 Colorado River bottoms and along the Gulf coast. 



Six acres of 13-year-old trees yielded $254.84 per acre. The bark 

 brought about $139 (5.9 tons at $23.31 per ton). The wood sold for 

 fuel yielded about $114. 



According to Mr. Smith, one man with good tools and a team can 

 take care of 250 acres of black wattles with ease when it has once 

 been sown and thinned. "One pound of good seed should plant 

 10 acres." This illustrates scientific progress, since many planters 

 have been in the habit of sowing 5 or 10 pounds to the acre. Yet 

 Acacia pycnaniha has about 23,800 seeds to the pound; A. normalis, 

 about 28,500, and mollis 38,500. The present Australian practice is 

 to sow from one-third of a pound to a pound of seed an acre, but since 

 1,200 trees is an abundant stand and 800 is better, a pound of good 

 seed should sow 10 or more acres. In the famous Tantalus acacia 

 plantation in Hawaii, the trees of 13 years vary from 6 to 18 inches. 

 A 10-year-old tree would yield 100 pounds of green bark, which is 

 equal to 50 pounds dry. The best trees yield as much as 200 pounds. 



Tanbark Acacias in California. 



While there are no commercial plantations of tanbark acacias in 

 the United States, the leading tanbark acacias have long been grown 

 at the California Experiment Station at Berkeley and at various sub- 

 stations. Their product has been analyzed and compared with that 

 from the California oaks and from canaigre (Rumex hymenosephalus) . 

 In the bulletins of the California Experiment Station and of the 

 Federal Forest Service 2 attention has been called to the rapid disap- 

 pearance of California tanbark oak (Quercus densijlora), the tannin 

 from which has given high reputation to California-tanned heavy 

 leathers. The constantly increasing cost of the bark has been noted 

 and at the same time the deterioration of its quality, since mere 

 bushes and saplings are now being stripped for the thin young bark, 

 incomparably inferior to the old thick bark from the boles of mature 

 trees. The necessity of securing a supplement to or substitute for 



1 Bulletin 11, Hawaiian Experiment Station, 1906, "The Black Wattle in Hawaii." 



2 Bulletin 75, Forest Service, U. S. Department of Agriculture, California Tanbark Oak, by Willis Linn 

 Jepson, issued Sept. 20, 1911. 



