252 DISEASES OF TROPICAL PLANTS CH . 



common in open forests, orchards, and shade trees. 

 The sporophores are hoof-shaped, woody, and may be 

 either sessile or stalked, and the pores are narrow. 

 Fames semitostus, Berk., has been reported as a root 

 disease on the Para rubber tree (Hevea braziliensis) 

 in the Straits Settlements and Federated Malay States 

 (see page 195). It has been also reported on the 

 cacao in Ceylon, and probably attacks many other trees. 



Polyporus. The various species of this genus are 

 also very destructive in the temperate zones and have 

 been frequently reported from the tropics, but have 

 not been thoroughly studied. They are also wound 

 parasites, and the sporophores are very similar to 

 Fomes, except that these are at first fleshy and later 

 become hard. They also vary greatly in shape. 



P. hispidus, (Bull.) Fr., is the best known. It 

 occurs on the trunk of the mulberry trees in Europe. 

 It is a wound parasite, and attacks the trunk and larger 

 branches, causing the heart wood to rot. P. obliquus and 

 P. fumosus are reported as parasitic on the orange in 

 Malta, P. Jlavus on coffee, and an undetermined species 

 has been reported on the stems of rubber, tea, and 

 other plants, but has not been studied. 



Agaricus. Many of the species belonging to the 

 genus Agaricus are the causes of parasitic diseases and 

 saprophytic rots. This genus is characterised by gill 

 or leaf-like structures over which are spread the basidia 

 or spore-bearing bodies. The genus also includes many 

 species that live on the decaying matter in the soil, 

 some of which are edible. 



Corticium. - - The fruiting bodies of the genus 

 Corticium have smooth surfaces, on which the basidia 

 are borne. It is widely distributed in tropical countries, 

 and attacks many plants. Among the most important 

 on cultivated trees are C. javanicum, Zimm., and C. 

 Zimmermanii, (Sacc.) Syd., which attack coffee, tea, 

 cacao, and rubber trees. Further knowledge of this 

 genus will no doubt prove that its species attack a 

 very large number of our forest and shade trees. 



