730 MINNESOTA BOTANICAL STUDIES. 



15. PODONPORIUM Schw. Syn. Amer. Bor. 278. 1834. 



Podosporella E. & E. Proc. Acad. Nat. Sci. Phil. 1894:385. 

 1894. 



Stipe erect, strict, black, composed of densely congested, 

 carbonaceous, rarely soft, hyphae, cylindrical or linear-subu- 

 late; sporophores short, lateral, typically simple; conidia scat- 

 tered, septate, fuscous, cylindrical, or clavate cylindrical. 



PODOSPORIUM CRUCIGERAE (SCHW.) 



Dematium ciiicigerae Schw. Syn. Car. 129. 1822. 



Podosporium rigidum Schw. Syn. Amer. Bor. 278. PI. 19. f. 1. 1834. 



PODOSPORIUM HUMILE (E. & E. 



Podosporella liumUis E. & E. Proc. Acad. Nat. Sci. Phil. 1894: 385. 1891. 



Family TUBERCULARIACEAE (Ehrenb.) 



Tuberculariei Ehrenb. Sylv. Myc. Berl. 12. 1818. 



Sporophores collected in a waxy or gelatinous, wart-like 

 head or tuft (sjjorodochium). 



Although they grade into the Stilbaceae to some extent, the 

 Tubercular iaceae are well distinguished as a group of the 

 Hyphomycetes. On the other hand, the black or dark-colored 

 genera approach so closely to the Melanconieae that many of 

 them are not to be placed with certainty in either group. Sev- 

 eral genera have been placed at various times first in one and 

 then in the other by the same author. Thus Epiclinium was 

 first put in the Melanconieae as a sub-group of Didymosporium 

 by Saccardo, who later separated it from Didymosporium and 

 placed it in his Tubercularieae. Some of these genera also ap- 

 proach genera placed in the Sphaeropsideae, especially in Nec- 

 trioideae and Excipulaceae. Sometimes the ambiguity extends 

 only to a few species in a genus, as in Trimmatostroma, in which 

 certain species are clearly of the Melanconieous type, while 

 our T. americana is rather of the Tuberculariaceous type. 

 Among the Sphaeropsideae, Cyphina and Paiellina in the Nectri- 

 oideae, Dinemasporium and Amerosporium in the Excipulaceae, 

 and some species of Lepioihyrium in the Leptostromaceae might 

 well be placed with some Melanconieae and with some Tuber- 

 culariaceae. Compare with these genera some Volutelleae. 

 Saccardo has placed Paiellina both in Excipulaceae and in 

 Tuber culariaceae, adhering at length to the latter view. It is 

 apparent, then, that it is largely a matter of personal taste 

 where such groups are placed. 



Schrceter,* evidently with these difficulties in mind, separated 



Krypt. Flor. v. Scliles. Pilz. 32 : 8. 1893. 



