296 



I'm: \i;mii»icm 



Uredospores. Sori yellow, roundish, often confluent, pul- 

 verulent; spores ellipsoid to ovate distantly verruculose, yellow, 



28—32 x21— 24 ^ 



Teleutospores. Sori hypophyllous, large, roundish, thick, 

 pulvinate, black, on conspicuous purple-bordered spots; spores 



Fig. 224. Ph. violaceum. a, aecidiospore ; b, uredospore; c, outlines of various 

 mature teleutospores from the same sorus ; d, young teleutospore before 

 the middle coat is fully developed, showing the fusion-nucleus in each cell, 

 and the gelatinous outer coat; e, mature teleutospore, the pearl-like drops 

 are caused by the shrinking of the outer coat ; c x 200, the rest x 600. 



cylindrical, of 1 — 5 (mostly four) cells, rounded at both ends, 

 with a short yellowish papilla at the apex, hardly constricted, 

 verrucose, brown, 65 — 100 x 30 — 35 /x ; two germ-pores to each 

 cell ; pedicels long, colourless, swollen at the base. 



On Rub us fruticosus. Very common, especially near the 

 coast. August — November. (Fig. 224.) 



This species is easily distinguished by its large conspicuous red and 

 purple spots, and on microscopical examination by the predominance of 

 four-celled teleutospores. These pass the winter on the leaves, which often 

 remain green on the plant ; they germinate with the greatest readiness in 

 April. It is an interesting fact that on some portions of the coast, such 

 as in North Wales, this species predominates, but on other portions, 

 e.g. in parts of Yorkshire, as I was informed by the late Mr. R. H. Philip, 

 its place is largely taken by P. Rubi. 



Distribution : Europe, Egypt. 



