632 



NOTES ON THE NATIVE FLOKA OP N. S. WALES; IX., 



the latter are white, and, as pointed out by Maiden and Betche, 

 the stigma of the former is entire or nearly so, while that of the 

 latter is more or less lobed, or nearly entire.* 



The discovery of this variety of Asterolasia, on the Nandewar 

 Mountains, is of special interest, as although it is not uncommon 

 in Victoria, it has only once previously been recorded for New 

 South Wales, having been collected by Mr. Forsyth at Lobb's 

 Hole near Kiandra, in November, 1900. Its occurrence at 

 Mount Lindsay extends its range northerly a distance of about 

 400 miles, and it still remains unknown to botanists in the inter- 

 vening area. 



In order to try and account for the present distribution of this 

 plant, particularly its isolation on the Nandewar Mountains, 

 several possible causes have to be considered, and the problem is 

 difficult of final solution. Examples of isolated occurrences of 

 plants, such as this, all furnish some slender evidence of what 

 former land-surfaces or climatic conditions may have been, and 

 an aggregation of similar facts, obtained by constant observation 

 and collecting, largely assists in the solution of such problems. 



Three of these possible causes, which suggest themselves, are: 

 first, dispersal by birds; second, gradual spreading from parent- 

 plants; and third, stranding through change of climate in inter- 



vening areas. 



Possible distribution by birds is an important factor, which 

 should never be overlooked, as seeds may be dispersed over a very 

 wide area, and young plants may only grow wliere the conditions 

 are suitable for the particular plant. This variety of Asterolasia, 

 however, is so rare in New South Wales, that if its occurrence 

 on Mount Lindsay is the result of dispersal by birds, it is difficult 

 to understand why it does not occur in many more localities nmch 

 less than 400 miles northerly from Kiandra. It is possible that 

 it may have been overlooked in some spots, but various collectors 

 have been over a great portion of this area, so that it is unlikely 

 that its occurrence is other than rare within the limits mentioned. 



*.l. H. Maiden, F.L.S., and E. Betuhe, These Proceedings, 1901, p.80; 

 and 1902, p. 56. 



