472 Durand : Classification of the Fleshy Pezizineae 



largely based. In the following pages numerous examples will 

 be studied in order to determine what characters may be safely 

 used as bases for such family grouping. 



Family PEZIZACEAE 

 Discina Stephensoniana Ell. 



This species grows on rotten wood. The plants are usually 

 crowded and irregular with a short, fleshy stem. The cups are 

 3—8 cm. in diameter, with a flat or concave disk, and a recurved 

 or laciniate margin. The flesh is light cinnamon brown, but whit- 

 ish beneath. 



This is a very interesting plant as far as the structure of its 

 sterile layers is concerned. Beginning at the lower surface there 

 appears first a layer of pseudo-parenchyma composed of very small 

 thin-walled, polygonal cells. They average about 6-8 fi in diam- 

 eter. Just above this layer is one of about equal thickness, com- 

 posed of quite large, polygonal, isodiametric cells 30 fi in diam- 

 eter. These cells show little or no trace of their hyphal origin. 

 Joining this layer with an abrupt transition is a rather thin one 

 of coarse hyphae, with frequent septa. Septation and coalescence 

 have not advanced so far in these threads that the hyphal form is 

 lost. 



The transition from hyphae to pseudo-parenchyma is very 

 nicely shown in the thick layer just above the hyphal one last 

 described. The tissue is composed of stout hyphae loosely inter- 

 woven with large interhyphal spaces. These hyphae are much 

 septated, and often coalesce, thus giving rise to many polygonal 

 cells measuring from 15 to 90 fi in diameter. The thin layer im- 

 mediately beneath the hymenium is composed of similar cells, 

 among which the asci may be traced down for some distance. 



Discina Warnei Peck 



The sterile layers in this species are composed throughout of 

 very coarse hyphae which are much bent and septated so as to 

 resemble a pseudo-parenchymatous tissue. In the looser portions 

 individual threads may be traced for some distance. In these, cer- 

 tain portions are seen to be much swollen so as to be almost vesic- 



