THE DISCOMYCETES OF EASTERN IOWA. 293 



Genus I— C ENANGIUM Fries. 



Cups scattered or tufted at first immersed, then breaking 

 through the substratum, 'sessile, leathery or waxy, brown or 

 blackish. Receptacle, cup-shaped. Asci clavate, 8-spored, 

 elongated, cylindrical or fusiform, straight or curved, spores 

 i-celled, hyaline, in 2 rows. Paraphyses enlarged at their 

 apices, forming an epithecium. 



One species collected in the northeast part of the state, on 

 limbs of Popidus tremuloidcs. 



Cenangium populneum {Pers.) Rchm. 

 Plate XXV., fig. i. 



1891 Pcziza populnea Persoon, Syn. Fung., II, p. 671. 



1889 Cenangium populneum Saccardo, Sylloge Fung., VIII, p. 565. 



L897 Cenangium populneum Engler-Prantl, Pflan. Famil., p. 232. 



Cups sessile, caespitose, 3 to 7 mm. in diameter, often very 

 irregular, forming dense rosettes springing from beneath the 

 epidermis, or solitary, dark brownish black; hymenium con- 

 cave; margin irregularly lobed, often splitting; asci clavate; 

 sporidia oblong, or fusiform, elongate, 12 to 14 by 3 to 4 mic- 

 rons, each containing 1 small central guttula; paraphyses fili- 

 form, slender, slightly enlarged upwards, often branched. 



Habitat — On dead branches of Popuhis tremuloidcs. Col- 

 lected by B. Shimek, Howard Co., Iowa; early spring. 



Plants spring from beneath the epidermis of the host and 

 often form rosettes nearly an inch in diameter, or a ring 

 which extends nearly around the branch. The plants are 

 crowded together so as to become very irregular, sometimes 

 compressed and twisted in various shapes. They are quite 

 easily recognized by these characters. The spores are often 

 much curved with a very small guttula in the center. 



Genus II— B ULGARIA Fries. 



Cups gregarious with a short thick stem. Growing at first 

 under the bark then breaking through. Externally dark col- 

 ored, rough, often with short hairs, gelatinous, shrinking when 



