COLCHICUM SMUT 



227 



' UREDINACEAE 



CoLCHicuM Smut 



{Uromyces colchici^ Massee.) 



For three successive seasons the fohage of a bed of 

 Colchiciun speciosum was completely destroyed by this 

 fungus, and during the third season plants of Colchiaifti 

 bavaricum and C. aiituinnale growing on either side of the 



■-- 1 



^^>^. 



Fig. 56. — Uromyces colchici, i, portion of a diseased 

 Colchicum leaf ; 2, a sorus or cluster of spores which 

 has ruptured the epidermis of the host-plant, x 10 ; 

 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 



