Nebraska Forest Fungi. II 



95 



or light colored, waxy, corneous or somewhat membranous in 

 certain cases, but lacking the more or less well developed jacket 

 of sterile tissue characteristic of the pycnidium of the Sphac- 

 ropsidales. 



Mclanconiaccae: 



With the Characters of the order. 

 Marsonia 



In this genus the acervuli are always long covered by the 

 -epidermis or cuticle, they are globose-discoid in shape, and pale. 

 Spores ovoid, fusoid, or oblong, 1-septate, hyaline. 



Marsonia juglandis (Lib.) Sacc. 



Spots on the upper side of the leaflets, circular, or irregular, 

 dark, becoming ashen colored. Acervuli flattened, rough, brown, 

 very small, scattered over the discolored spots. Spores fusoid, 

 curved, pointed at the ends, 1-septate, hyaline, 20-25x5 microns. 

 Common on the leaflets of Jug fans nigra. 



Marsonia martinii Sacc. 



Discolored spots on both sides of the leaf, minute, yellowish. 

 Pustules or acervuli gregarious in the center of the spots, often 

 on the lower surface, globose, minute. Spores fusoid, curved, 



acute at both ends, 1-septate, 

 slightly constricted at the sep- 

 tum, hyaline, guttulate, 15x2.5 

 microns. Basidia very short, 

 greenish. On fallen leaves of 

 Querciis macrocarpa. The dis- 

 colored spots with the orange or 

 yellow pustules are usually very 

 evident after the leaves fall. 



Marsonia castagnei (Desm. & 

 Mont.) Sacc. 



The orbicular, confluent, 

 brown, spots of this species oc- 

 cur on the upper side of the leaf. 

 The spores are oblong-clavate, 

 1-septate, not at all or only 

 slightly constricted at the sep- 

 tum, hyaline, very short pedicil- 



Habit of acervuli in leaf. b. Sec- 



tion of acervulus on leaf. Highly 

 magnified. 



late, 18-20x7-8 microns. 

 Populus alba. 



On 



