64 DISEASES OF TROPICAL PLANTS OH, 



(see page 160), of the coffee is probably the most injurious 

 of any of the tropical rusts. 



Puccinia sorghi, Schw., and P. purpurea, Cooke, 

 of corn, and P. purpurea, Cooke, on millet, broom corn, 

 and Kaffir corn, are more or less common in tropical 

 countries where these crops are grown (page 96). 



Uromyces appendiculatus, Thax., attacks the beans ; 

 U. pisi, (Pers.) De Bary, the peas ; U. Zoffrini, the 

 vanilla ; and U. betae, Frank, the beet. 



Uredo scabies attacks the vanilla ; U. arachidis 

 is a serious pest on the peanut ; Z7. gossypii, Lager, is 

 a serious pest on cotton ; U. kuehnii, Wakker and Went. , 

 on cane ; and U. jici, Cast, of the fig. 



Coleosporium ipomoeae, (Schw.) Burr., of the sweet 

 potato, is also very widely distributed. 



The Autobasidiomycetes, sometimes called the higher 

 Basidiomycetes, includes the great mass of more or less 

 fleshy fungi which are usually referred to as mushrooms, 

 toad-stools, punks, etc. They are masses of mycelium 

 which have assumed more or less definite forms, although 

 extremely variable in size and shape. The great 

 majority are saprophytic, but many of them may, 

 under certain circumstances, assume parasitic habits. 

 They are the cause of many diseases and wood rots. 



The Auriculariales include a number of fungi which 

 are jelly-like in character, and which may grow singly 

 or in masses. 



The Exobasidiales are always parasitic, and produce 

 deformities of the host plant. These deformities are 

 frequently gall-like in nature, and are composed of 

 tissues of both host and fungus. Exobasidium vexans, 

 Massee, of the tea belongs to this order (page 172). 



The Hymenomycetales includes the families Thelo- 

 phoraceae, Hydnaceae, Polyporeaceae, and Agariaceae. 



In the Thelephoraceae the hymenial or spore-bearing 

 surface is usually smooth and continuous. The two 

 most important genera are Corticium and Hymenocliaete, 

 which attack many plants, especially trees. Among 

 the most important are C. javanicum, Zimm., of the 



