MEL A NCONIA LES 



73 



The diseases caused by the fungi of this order are known as 

 anthracnosc and are chiefly produced by species of the genera 

 Gloeosporium and Colletotrichum. Among these are the anthrac- 

 nose of the bean, cotton, hollyhock, melon, pepper, spinach, to- 

 mato and watermelon caused by members of the latter genus ; and 

 those of the apple, "* blackberry, cucumber, currant, peach, a 

 second on pepper, persimmon, raspberry, rose and a second on 

 tomato caused by species of Gloeosporium. The anthracnose of 

 the chestnut is caused by a species of Marsonia. 



Of the thirty six genera the following are the principal ones con- 

 taining leaf parasites : 



1. Conidia i-celled, globose, ovoid or short cylindric, hyaline. 2. 

 Conidia filiform, often twisted ; acervuli pale. CYL1NDROSPORIUM. 

 Conidia fusiform-falcate ; acervuli black or gray. CRYPTOSPORIUM. 

 Conidia 2- celled, solitary. MARSONIA. 

 Conidia 3-many-celled, smoky. 5- 

 Conidia 3-many-celled, hyaline ; acervuli pale. SEPTOGI.OEUM. 



2. Conidia with branched bristles at apex. PESTALOZZIELLA. 

 Conidia not spiny. 3. 



3. Acervuli bristly at the margins. COLLETOTRICHUM. 

 Acervuli not provided with bristles. 4. 



4. Acervuli soon erumpent, minute, bright colored. HAINESIA. 

 Acervuli long covered, gray or pallid, somewhat waxy. GLOEOSPORIUM. 



5. Conidia with hyaline cilia at apex. PESTALOZZIA. 

 Conidia oblong, not ciliate or rostrate. CORYNEUM. 



Of the above genera Gloeosporium is the largest with some one 

 hundred and twenty five species and Pestalozzia follows next with 

 about ninety. Besides the leaf parasites a common twig parasite 

 may be seen on young twigs of Cornus causing them to turn yel- 

 low and die, when they are covered with the erumpent acervuli of 

 Myxosporium n itidiun . 



LITERATURE. 



Saccardo. Sylloge Fungorum, 3 : 696-812 ; 10 : 446-509 ; n : 

 562-585. 



Ellis & Everhart. The North American Species of Gloeospo- 

 rium. Jour. Mycol. i : 109-120. 1885. 



* Also called ripe rot. 



