461 



FUCCINIA ON GROUNDSEL, WITH TRIMORPHIC 

 TELEUT08P0RES. 



By D. McAlpixe. 



(Communicated hij J. H. Maiden.) 



(Plates xxxiv.-xxxvi.) 



A specimen of Oroundsel Rust was sent to me by Mr. Rod way, 

 of Hobart, Tasmania, and found by him there on the 21st April 

 of the present year. The aecidial-stage of the Groundsel Rust is 

 common enough, at least with us at the Royal Horticultural 

 Gardens, Burnley, but as he informs me this is the first and only 

 instance in which he has found the black rust with teleutospores. 

 At present, and indeed throughout the year, there is plenty of 

 Groundsel with aecidia at the Royal Horticultural Gardens, but 

 I have hitherto failed to find any teleutospores, and they are 

 here recorded for the first time in Australia on Groundsel. But 

 last year* I described a Facciaia on Erechtiies, a. genus closely 

 allied to Senecio, received from Mr. Robinson, of Ardmona, and 

 on comparing the two forms I find that the Groundsel Rust is 

 very similar. 



Description. 



I. Aecidiospores. — Aecidia forming blister-like swellings on stem 

 and l^ranches, on upper and undersurfaces of leaves, on flower- 

 head stalks and involucre, causing discolouration and distortion 

 and usually surrounded by paler green tissue; the}^ are disposed 

 in clusters without any definite order. 



Pseudoperidia round, sometimes oval, with white, scolloped 

 everted edges; before opening tubercular. 



Aecidiospores spherical, oval or angular, orange-coloured, 

 smooth, average 14-16 /x in dia. or 14-17 x 12-16 fx. Very com- 

 mon all the year round, except during middle of summer. 



* Proc. Roy. Soc. Vict. Vol. vii. N.S. pp. 214-221 (1894). 



