MYCOLOGIA 



Vol. XIII MARCH, 192 1 No 2 



PHOTOGRAPHS AND DESCRIPTIONS OF 

 CUP-FUNGI— IX 



NORTH AMERICAN SPECIES OF DISCINA 



Fred J. Seaver 

 (With Plate 4) 



The genus Discina was established by Fries in 1849 as a mono- 

 typic genus, having been segregated from the old genus Peziza 

 and based on Peziza perlata of Fries which, so far as we can see, 

 is identical with Peziza ancilis of Persoon. The species is char- 

 acterized by the thick waxy consistency and the expanded form 

 of the apothecia. The spores of the species also furnish impor- 

 tant diagnostic characters, although these were not mentioned by 

 Fries when the genus was proposed. The spores are unusually 

 large, strongly roughened at maturity, and provided with an 

 apiculate appendage at either end. 



Although the genus originally contained a single species, it has 

 been gradually enlarged until at present it contains a score or 

 more of species. In fact, almost every species which shows a 

 tendency to 1 become repand or flattened has finally come to be 

 placed in the genus Discina. 



After an extended study the writer, while recognizing the 

 genus, is inclined to use it in a more restricted sense to include 

 those large forms of cup-fungi which have appendiculate spores 

 since the spore characters are more fixed and reliable than the 

 mere form of the apothecia which is so susceptible to change. 

 The genus would then include comparatively few but well marked 

 species. 



[Mycologia for January (13: 1-65) was issued February 3, 1921] 



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