486 FUNGI IMPERFECTI. 



Myxosporium. 



Conidia ovoid, hyaline, and abjointed from rod-shaped basidia 

 situated in cavities of the cortical tissues of arboreous plants ; 

 a true pycnidium is not formed, and the reproductive mycelium is 

 only covered over by the epidermal layers of the host. 



Myxosporium devastans Eostr. 1 is said to attack and kill 

 young twigs of Bcttda verrucosa. The conidial patches are 

 developed in the killed rind, and give off unicellular colourless 

 conidia. 



M. carneum Li1>. is parasitic on twigs of beech. 



M. laneola Sacc. et Roum. causes death of oak-twigs. 



The other known species have as yet been observed only as saprophytes. 



Colletotrichum. 



Conidial patches surrounded by setae ; characters very like 

 Grloeosporium. 



Colletotrichum Lindemuthianum (Sacc. et Magn.).- This 

 disease, first observed by Lindemuth in 1875, has assumed 

 great importance as a disease of the kidney bean (Phaso '/>'>< 

 vulgaris) both in Europe and America. Young pods are most 

 frequently attacked, but neither stems nor leaves are exempt. 

 The pods show brown depressed spots with a distinct margin. 

 The unicellular and oblong conidia are given off from short 

 conidiophores developed on the spots. Germination takes place 

 at once, the germ-tube forming an adhesion-disc on the host- 

 epidermis, and from this a hypha penetrates into the tissues 

 to develop into a brown mycelium. Frank obtained brown 

 spots and mycelium on young beans twenty-four hours after 

 infection. 



C. Lagenarium (Pass.) (C. oligucJutifm,, Cav.). This parasite 

 is very injurious to seedlings of water melon (Cm-uiiiix r//, //////*), 

 melon (C. JL'f<>) } and the gourd (Cncurbita Ln<in/ri<i}. Leaves 

 and fruits may be attacked, but it is the cotyledons and steins 

 of the seedling plants which most frequently fall a prey. Spots 



1 Rostrup, Tidsxkriftf. Skorraextn, 1893. 



-For the relationship of this with the following species, as well as their 

 synouomy, see Halsted in Bulletin of Torrey Botanical Clul>, 1893, p. 246. 

 Description, treatment, and bibliography by Beach, " Bean-spot disease," Gtntm' 

 j.V. F. E.'ir. station Bidhtin, No. 4s. ' 



