580 NOTES ON THK NATIVE FLOUA OF NEW SOUTH WALES, viii., 



New South Wales, and are known as Swamp Gum, a rather mis- 

 leading name, and one more suitable for E. acervula. (For 

 previous remarks on E. fasfigata, see these Proceedings, 1902, 

 p.588). 



E crebra, usually known as Narrow-leaved Ironbark, and 

 having a red timber, and very small fruits, is the common Iron- 

 bark of the felsitic-area around Yerranderie and Colong. IJarral- 

 lier's entry of the 24th November, 1802, refers to tlie quartz- 

 felsite country (which he called granite) between the South Peak 

 and Alum Hill, near Colong, and is as follows: — "The trees there 

 are the blue gum and ironbark, of medium height. The most 

 abundant stones are the blue granite. The plants are similar to 

 those in the environs of the Hawkesbury." 



The blue gum and ironbark mentioned are E. tereticornis and 

 E. crehra respectively; and the above is his last entry concerning 

 ironbark, as, on the following day, he ascended to elevations 

 above that at which this tree grows. 



E. crehra occurs in Queensland, but after coming into New 

 South Wales, on Northern New England, at altitudes up to 3,000 

 feet, the colder southern portion of the Main Divide causes it to 

 spread south-westerly, to about Dubbo on the one hand, and 

 down the East Coast on the other. It is common along the 

 Goulburn River, a tributary of the Hunter, where the low portion 

 of the Liverpool Range allows it easy access on to both the 

 eastern and western watersheds. It appears to prefer soils rather 

 acid than basic; and its presence would usually indicate that the 

 rock upon which it was growing contained over 60% silica. At 

 the same time, the Hawkesbury Sandstone appears to be generally 

 too acid for the species. It will flourish on a fairly sandy soil 

 right up to within a few yards of basalt containing only 45% 

 silica, but producing an excellent soil, when it will cease abruptly. 

 It may not be the amount of silica in the soil which regulates its 

 distribution, but possibly its objection to the greater quantity 

 of either ferrous oxide, magnesia or lime usually found in the 

 more basic rocks, or it may prefer the potash, which is a con- 

 stituent generally occurring in greater amount in the more acid 

 formations. There are other ingredients which may have a 



