THE DISCOMYCETES OF EASTERN IOWA. 257 



Family I— PYRONEMACE^S 



Receptacle seated on a mass of thread-like hyphae. Hym- 

 enium at length plane or snbconvex. Peridinm wanting or 

 poorly developed. 



Genus I— P Y R O N E M A Cams. 



Receptacle seated on a mass of hypha?, fleshy, at first spher- 

 ical, then expanded. Peridium very poorly developed or 

 wanting. Sporidia elliptical, hyaline. 



KEY TO THE SPECIES. 



a — Plants very minute, crowded, on charcoal . P. aurantio-rubrum. 

 b — Plants larger, scattered, on burnt ground . P. melaloma. 



Pyronema aurantio-rubrum {Fckl.) Sacc. 

 Peate IV, fig. 1. 



1823 Peziza omphalodes 



a. aurantio-rubrum Fries, Syst. Myc. , II, p. 73. 

 1889 Pyronema aurantio-rubrum Saccardo, Sylloge Fung., VIII, p. 73. 



Receptacle fleshy, distinct, gregarious or crowded, 1 mm in 

 diameter, sessile, brick red or paler; hymenium plane; asci 

 cylindrical, 8-spored; sporidia elliptical, 8 to 9 by 5 to 6, 

 microns, 2 to 3 guttulate, granular within, paraphyses en- 

 larged upwards and filled with colored granules. 



Habitat — On charcoal and ashes where fire has been in the 

 fall; Iowa City. 



These plants grow closely crowded together on charcoal 

 and surrounding soil forming large reddish masses in such 

 places in the fall of the year during very wet weather. This 

 species is distinguished from Pyronema omphalodes (Bull) 

 Fckl., as described in Saccardo by the much smaller sporidia. 

 A plant collected at Lafayette, Indiana, by a student of Purdue 

 University, seems to conform to the description of P. ompha- 

 lodes Bull. These plants were collected on clay which was 



