﻿AN ECONOMIC STUDY OF ACACIAS. 17 



decurrens in importance for its yield of tanner's bark; the quality of 

 the latter (A. pycnantlia) is sometimes even superior to that of the 

 black wattle, but the yield is less." Dr. Maiden says it is "one of the 

 richest tanning barks in the world; a richer may exist, but I do. not 

 know of i.t." The sample bark that he analyzed in 1880, by Low- 

 enthal's improved process, showed tannic acid 46.47 per cent, extract 

 74.07 per cent. This was, of course, an extremely rich sample. 

 Thirteen samples from the Government farm at Bellair, South Aus- 

 tralia, taken from trees at various ages and grown on different soils, 

 ranged from. 28.5 to 38.5 per cent tannic acid and from 57.75 to 

 68.35 per cent extract. The trees were from 3 to 7 years old; the 

 soils were light and shallow and mostly on a bedrock of hard 

 sandstone. 



This is the true golden wattle of Von Mueller, and when in bloom 

 it is strikingly attractive. It is considerably smaller than any of the 

 A. decurrens forms; hence it may not yield as much bark per acre as 

 Acacia decurrens mollis. But the trees can be set closer . together, 

 and the quality of the product is unsurpassed. 



ACACIA DECURRENS DEALBATA. 



Good barks of Acacia decurrens dealbata, or silver wattle, contain 

 about 25 per cent of tannic acid. In some situations it grows faster 

 than the normal A. decurrens, and when full grown always forms a 

 stately tree. It requires rich moist soil and a frostless locality. On 

 river banks in Australia it reaches a height of 150 feet; in California 

 the largest recorded specimen is 90 feet high and 2\ feet in diameter. 

 Several considerations militate somewhat against its planting. In 

 the first place, it will hardly pay to plant it where the more produc- 

 tive A . pycnantha and A . decurrens will thrive ; and it is not frosthardy. 

 The root system of A. dealbata, like that of A. melanoxylon, is mainly 

 at the surface, and the trees are easily blown over. 



ACACIA MELANOXYLON. 



The appearance of Acacia melanoxylon, the black wood of south- 

 eastern Australia, is very different from that of the feather-leafed 

 acacias. It belongs, with Acacia longifolia, A. pycnantlia, and most 

 of the Australian species, to the wonderful phyllodinous acacias. 

 With these the true leaves are suppressed, or nearly so, and the flat- 

 tened leaf-stalks (phyllodia) perform the functions of leaves. The 

 first foliage from seedlings of any of these species are delicate, 

 feathery, bipinnate leaves; but the leaf-stalk soon broadens, length- 

 ens, and hardens, finally changing to a leathery phyllodium. Some- 

 times a few of the true leaves will persist for a long time at the 



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