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 sou, 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, spécies which seem most desirable for American plantations, 
for rapid reclamation and maximum profit are A. pycnantha, 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 sophore, 
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. pycnantha and A. decurrens it 
isa 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 A. cyanophylla (bluewattle), A. decurrens 
var. mollis and A. baileyana, as well as A. pycnantha. All these thrive 
near the seashore and on light soils. Acacia longifolia, cyanophylla, 
and pycnantha 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. bacleyana 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 Albizzia 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. 
