COLCHICUM SMUT 



227 



UREDINACEAE 



CoLCHicuM Smut 



{Uromyces cokhici, Massee.) 



For three successive seasons the foliage of a bed of 



Cokhicum speciosum was completely destroyed by this 



fungus, and during the third season plants of Cokhkmn 



bavarkum and C. autiminak growing on either side of the 



Fig. 56-— Uromyces coUhici. ±, portion of a diseased 

 Colchictim leaf; ^, a sorus or cluster of spores which 

 has ruptured the epidermis of the host-plant, xio ; 

 3, teleutospores, consisting of several cells united in a 

 cluster ; the central dark cells are fertile, the pale, peri- 

 pheral cells are sterile, x 300. 



diseased patch were also attacked, although escaping for 

 the first two seasons. The parasite attacks the leaves 

 only, commencing at the base of the leaf-sheath and 

 gradually extending towards the tip of the leaf The lowest 

 and oldest leaf is first attacked. 



The sori or spore-clusters are very much larger than is 



