472 FUNGI IMPERFECTI. 



A new genus Charrinia, belonging to the Sphaeriaceae of the 

 Ascomyeetes, has been formed to receive this species. 



Sphaeropsis. 



Pycnidia black and spherical, with an aperture. Conidia ovoid 

 or oblong, unicellular, dark-coloured, and on stalk-like conidio- 

 phores. 



Sph. malorum Peck. The cause of a disease in America, 

 known as the black-rot of apple and quince. The mycelium 

 permeates and destroys the skin of the fruit, which, in con- 

 sequence, becomes dried up and mummified. It also occurs in 

 Britain. 



Other species attack j)lants of various Eosaceae. 



Phaeodidtmae. 



Diplodia. 



Pycnidia, small, spherical, and dark-coloured ; the conidia are 

 two-celled when mature. 



Diplodia gongrogena Temme.^ Temme discovered a mycelium 

 and the pycnidia of this Diplodia in aspen {Populus tremulae) 

 exhibiting hypertrophied outgrowths of wood and rind. As yet 

 it has not been possible to artificially produce these malformations 

 on the aspen, nor other somewhat similar ones which occur on 

 the willow. 



Other species of this genus attack many trees, e.g. holly, lilac, 

 horse-chestnut, mulberry, and various conifers. 



Hyalodidymae. 



Ascochyta. 



Conidia ovoid or oblong, bicellular, and hyaline. The pycnidia 

 have a central aperture, and are embedded in discoloured portions 

 of leaves or twigs. 



The following species are of practical importance : 

 Ascochyta pisi Lib. (Britain). Briosi and Cavara state that 



' Temme, Landwirth. Jahrbuch, 1887. 

 Thomas, Verhand. d. bolan. Verein d. Prov. Brandenlmrg, 1874. 



