﻿AN ECONOMIC STUDY OF ACACIAS. 15 



sand has drifted in over the tops the trees have sprouted again from 

 below, and have formed impassable thickets. These close clumps 

 on pure sand do not seem able to grow higher than from 20 to 25 

 feet, but even this far surpasses the native scrub oak and willow. 

 As the park reclamation is made complete, however, and richer soil 

 spread out on the sand, Acacia decurrens and other large species 

 immediately begin to grow sturdily, and age for age are as handsome 

 and thrifty as those anywhere else in California. 



The especial value of these experiments upon California sand 

 dunes is the proof it gives that useful and ornamental plantations can 

 be made in such places. The natural desirability of residences on or 

 near the seashore is greatly increased if such homes can be sheltered 

 by groves and thickets. Acacias not only furnish these groves, but 

 help to retain the soil, furnish firewood, and, in the end, timber and 

 tanbark. Nearly all of the acacias are beautiful in leaf and flower 

 and graceful in their growth. Along the California coast, therefore, 

 as on that of the Mediterranean, they should be extensively planted. 



Correlating the Golden Gate Park and the South African experi- 

 ments, species which seem most desirable for American plantations, 

 for rapid reclamation and maximum profit are A. pycnaniha, decurrens, 

 leiophylla, and longifolia sown in combination with shrubby species 

 which will give way when the sands are fixed and forest conditions 

 established. The shrubby form of A. longifolia is the variety sophorse, 

 the spreading coast wattle; the tall form which might follow this is 

 the Sydney golden wattle, the bark of which yields from 15 to 20 per 

 cent of tannin, used chiefly for sheepskins. When the sand-dune 

 area has become well covered with A. pycnaniha and A. decurrens it 

 is a tanbark proposition. If the object is mainly shelter and beauty, 

 with the production of some tanbark as a secondary consideration, 

 the final species would well be^l. cyanophylla (blue wattle), A. decurrens 

 var. mollis and A. bailey ana, as well as A. pycnaniha. All these thrive 

 near the seashore and on light soils. Acacia longifolia, cyanophylla, 

 and pycnaniha are the best ones for inland localities up to an eleva- 

 tion of from 2,000 to 2,500 feet in southern California, though the 

 amount of frost rather than the elevation furnishes the deciding 

 factor. In this list, all except A. bailey ana yield tanbark. A purely 

 ornamental plantation on the seacoast might include several hundred 

 species, and would be exceedingly attractive. 



Because of its rapid growth in California and its value as a shelter 

 and a sand binder ATbizzia lophantha should be extensively planted. 

 It is one of the best species for obtaining a quick sand cover, and 

 reproduces itself faster than any of the true acacias. It is particu- 

 larly advantageous as the extreme advance guard of acacia plan- 

 tations nearest to the shore. 



