686 BOTANY OF THE INTERIOR OF NEW SOUTH WALES, 



the higher portions of the stream, and the latter of the lower, but 

 for very many miles they overlap. On the Lachlan River both 

 species are represented from about 30 miles below Forbes up to 

 about 30 miles above Cowra; thence the Oaks continue upwards 

 and the Gums downwards. I have not been able to hear of any 

 Eiver Oak below Condobolin ; the trees, even in the Forbes 

 district, become fewer as the lower country is reached. The fact 

 of their ceasing altogether is the more remarkable when it is 

 remembered that every year there must be an enormous quantity 

 of seed carried down by the stream. Probably the soil along the 

 lower parts of the river is more of a salty nature than that at 

 higher levels, as I have seen the water from mining shafts in the 

 low country of the Lachlan district too salt to be used in the 

 engine boilers employed at the batteries. It is also known that 

 in drought times, at least in the Darling, the water becomes 

 brackish and even salty from the inflow of brine springs along 

 the bank of the river, and this may be the chief cause in prevent- 

 ing the growth of the Oak trees. The seeds germinate very 

 readily in damp places, and in the cracks of an old log lying in 

 the river I once counted 35 young trees varying from one to ten 

 feet high. They would probably ne\ er mature, as the expanding 

 roots would split the log, and the several parts would then be 

 likely to be carried away by floods. 



C. Cunninghamiana is usually a dioecious species, and on the 

 upper parts of the Lachlan in the month of April, when standing 

 on the hillsides overlooking the river, the trees bearing male 

 flowers can be readily distinguished by their colour from those 

 bearing female flowers. The same features may be noticed among 

 the Hawkesbury valleys in July with one of the Forest Oaks, 

 C. suherosa. 



All our Casuarinas with the exception of C. Camhagei (Belah) 

 have the common name of Oak, and yet they bear no outward 

 resemblance to the Quercus family or well-known English Oak, 

 differing both in bark and foliage. Still there is a tradition that 

 the early English arrivals noticed a similarity in the wood through 

 both species having medullary ra3's, and this feature suggested to 



