ON COMPOSITE 



141 



spores globose to ellipsoid, delicately echinulate, yellow-brown, 

 22 — 30 x 19 — 24 /j,, with two germ-pores. 



Teleutospores. Sori amphigenous and on the stems, scattered, 

 minute, punctiform, pulverulent, 

 blackish-brown ; spores broadly ellip- 

 soid, rounded at both ends, not 

 thickened above, not constricted, 

 very delicately verruculose, chestnut- 

 brown, 30 — 35 x 22 — 27 //., sometimes 



longer ; pedicels hyaline, short. 



& t J Fig. 93. P. Cyani. 



On Centaurea Cyanus. Not un- Teleutospores. 



common in gardens. June — September. (Fig. 93.) 



There is a similar species, P. montana, which occurs on the continent 

 on Centaurea montana ; it is distinguished by the much coarser warts of 

 the teleutospores, which are also relatively longer. Both these species, 

 like P. obtegens, permeate the whole plant with the mycelium of the 

 primary uredospores, but such infested plants of Centaurea can flower 

 freely, while those of Cirsiwm arvense never do. The mycelium of the 

 secondary uredospores, mixed with teleutospores, is more strictly localised. 



Distribution : Western and Central Europe. 



15. Puccinia Carduorum Jacky. 



Puccinia Hieracii Plowr. Ured. p. 185 p.p., see also p. 216. 

 P. Carduorum Jacky, Composit.-Puccin. p. 58. Sacc. Syll. xvi. 297. 

 Sydow, Monogr. i. 33. 



Uredospores. Sori generally hypophyllous, on very indis- 

 tinct spots, scattered, minute, pulverulent, cinnamon ; spores 

 globose or subglobose, densely echinulate, pale-brown, 22 — 28 p, 

 with three germ-pores. 



Teleutospores. Sori similar, but dark-brown; spores variable, 

 oblong to ovate, rounded above, not thickened, hardly at all 

 constricted, rounded below, verruculose, brown, 25 — 38 x 17 — 

 24 fx ; epispore thin ; pedicels hyaline, short. 



On Carduus crispus, G. nutans. Not common ; Yorkshire, 

 Clare Island, etc. 



