BY D. McALPINE. 465 



pucciiiia, and may therefore be dismissed, so that P. conglomerata 

 has only to be considered; of which A. senecionis is the recognised 

 aecidial stage. This aecidium is given by Dr. Cooke in his 

 " Handbook of AustraHan Fungi (p. 342) for New South Wales 

 and Victoria " for Senecio, but no species is mentioned; still the 

 presumption is that we have here its Puccinia-stage and so 

 resemblances and differences will have to be carefully noted. The 

 principal points of difference in the aecidial stage are that the 

 aecidia of the Groundsel rust are on pale green spots, not on 

 brown, and are not margined with black, but otherwise there is 

 general agreement, except that their spores are rather smaller. 

 It is in the Puccinia-stage, however, that the differences are most 

 marked, and for convenience may be shown in tabular form : — 



P. conglomerata. P. erechtitis. 



Length of teleutospore 24-52 fi 36-63 /x. 



Breadth „ 14-26 /x 15-25 /li. (agree). 



( surmounted by j 

 Apex ,, < pale or colour- - none. 

 I less papilla I 



T- 11! T 1 ( short or moder- f , 

 Lengch of pedicel j .^^^j^ ,^^g -j long. 



Persistence ,, very deciduous .. . decidedly persistent 



Thickness ,, very slender moderately stout. 



Colour „ hyaline often j^ellow tint. 



While a solitary character, such as the relative length of the 

 stalk, or its persistence, would not justify specific rank, still the 

 aggregate of relatively fixed characters, such as the apical papilla, 

 the length and persistence of the stalk, form specific distinctions. 



Finally, Dr. P. Dietel gives critical notes on all Puccinias 

 occurring on Senecio and allied Composite in his paper on 

 ^^Puccinia conglomerata und die auf Senecio und einigen ver- 

 wandten Composites vorkommenden Puccinien."* He remarks 

 there that recent writers have placed many different species in P. 

 conglnmerata and considers that P. senecionis, Lib., and P. expansa, 



'' Hedwigia. Bd. xxx. 291 (1891). 



