Flora of Australia. 55 



the stem-leaves bein^- iiiucli longer than they are broad instead 

 of nearly circular as in the present specimens, with less than 

 5 bracts : the number of bracts in the umliels of both forms 

 varies from 3 5. rarely more. The i>lant is native to the 

 Mediterranean re<i-ions, and has hence spread to Europe, Asia, 

 North America and Australia. 



BuRSAKiA SPINOSA, Cav. (Pittosporeae). 



Various forms of this pleomorphic species have been described 

 as distinct species at different times, upon variations in the 

 shape and size of the leaves, presence or absence of spines, 

 hairs, size of the adult plant, etc. Such characteristics are, 

 however, precisely those most liable to local adaptive modifica- 

 tions and least reliable as specific distinctions. A careful 

 examination of the 200 odd specimens from all parts of Aus- 

 tralia existing at the National Herbarium shows that 3 fairly 

 marked varieties of this species can be recognised, but that 

 even the most nuirked one (var. hicana) is connected with the 

 type and with the other varieties by numerous intervening forms. 

 The forms are : — 



Bursaria spinom. Cav. The " type '" form is merely what 

 remains when the three varieties are removed. It comes from 

 all parts of Australia, and includes at least 20 intermediate 

 forms. It varies from a shrub to a tree 40 feet high, and 

 is usually without spines. 



Var. incaua This form has long, narrow more or less pointed 

 leaves up to 3 inches or more in length, with a white tomentum on 

 the under surface. It is comnionest in tropical Australia, and the 

 pons are usuall v rather larger than in the other forms. In the west 

 and south of Australia specimens are found with shorter and 

 broader leaves, but the tomentum still present. {B. incaua, Lindl.) 



Var. luzurians. This has also large leaves, but they are shorter, 

 tomentum on the under side. In other respects it is identical 

 with the ■' type.'' It appears to be commoner in the S.E. of 

 broader and more obtuse than in var. incaua and have no 

 Australia, particularly in moist valleys near the sea coast, but 

 also extends as far North as Queensland. It may include the 

 B. tenuifdlid of liailey. (Flora of Queensland, p. 72), but no 



