ACACIA 463 



forests on dry stony soil, associated with A. Catechu, A. Latronum, A. leuco- 

 pJiloea, Prosopis spicigera, and other species, and on the poorest ground with 

 Balanites Roxhurghii and Gapparis aphylla. It is associated with Acacia 

 arahica on black cotton soil, but where this gives place to shallow murram or 

 calcareous soil with rock or a clay stratum near the surface it replaces that 

 species. 



The yellow flower-heads, which have a somewhat unpleasant odour, 

 appear from November to March, and the pods ripen from April to June. 



10. Australian acacias. Three important Australian acacias, A. decurrens, 

 Willd., A. dealbata, Link, and A. Melanoxylon, R.Br., have been introduced 

 into India, chiefly in the Nilgiris, but to some extent also in the Himalaya and 

 other hill tracts. In the Nilgiris they have become such a feature in the 

 landscape that a brief account of their introduction and propagation in these 

 hills will not be out of place. 



A general description of the topography and climate of the Nilgiris will 

 be found under Eucalyptus Globulus, the exotic tree par excellence in that 

 region. Australian acacias appear to have been introduced first in the 

 early forties of last century, mainly with the object of providing fuel, of 

 which there was a great shortage at that time. Although as plantation trees 

 they have been outclassed by Eucalyptus Globidus, still the acacias chiefly 

 A. dealbata and A. Melanoxylon, and to a smaller extent A. decurrens were 

 extensively planted, partly in mixture with eucalyptus and partly alone. 

 The actual area of pure acacia plantations owned by Government in 1912 

 amounted to 322 acres ; in addition there are considerable areas of eucalyptus 

 and acacias mixed, at elevations varying from 5,000 to 8,300 ft. These acacias 

 are also to be found along roadsides, on waste land, in private plantations, 

 and in gardens. A. dealbata has spread by root-suckers to such an extent as 

 to become in many cases a nuisance. 



The acacias appear to have been propagated from transplants and not by 

 direct sowings, and this system has answered well. Spacings of 6 ft. by 6 ft. 

 to 9 ft. by 9 ft. have been the general rule in plantations. The Government 

 plantations, whether pure or mixed with eucalyptus, are worked for the pro- 

 duction of fuel under the system of simple coppice. The rotation adopted until 

 recently was one of ten years, but in 1913 it was raised to fifteen years. Under 

 the coppice system, A. Melanoxylo?i is gradually dying out, and in a few 

 unimportant cases it is being maintained, where pure, as high forest. Where 

 acacia is mixpd with eucalyptus the resulting crop becomes a two-storied 

 coppice, owing to the more rapid growth of the eucalyptus. 



The following particulars regarding the three acacias in question may be 

 of interest : 



(1) Acacia decurrens, Willd. Green wattle. An evergreen tree ; bark 

 olive green when young, dark grey on older trees. Branchlets and foliage 

 nearly glabrous and not hoary ; decurrence of leaf-stalks very marked. Flowers 

 paler yellow and less plentiful and less strongly scented than in A. dealbata ; 

 pods narrow and constricted between the seeds. Maiden describes six varieties, 

 but admits that the gradations from one to another are slight. Var. mollis, 

 Lindl., has tomentose foliage, but the pubescence on the branchlets is golden 

 yellow ; this variety is regarded in Australia as the best tannin producer 



