282 



Mycologia 



The spores of Daldinia vernicosa are peculiar in that, when 

 mounted in dilute (5 per cent.) KOH or NaOH, the exospore 

 wall, which is colorless, quickly dehisces and separates from the 

 spore, which is dark-brown. A single peripheral line of dehiscence 

 occurs at the center of the spore and the two halves of the exo- 

 spore wall usually break away from one another as two valves, 

 or they may dehisce partially and bend backward as if they were 

 hinged, thus allowing the spore to free itself from its peripheral 

 membrane (Fig. 1). The spores of Daldinia concentrica also ex- 

 hibit the same behavior, and, with equal facility. These obser- 

 vations on the dehiscence and shedding of the colorless exo- 

 spore wall of these two species, when the spores have been 

 mounted in dilute solutions of KOH and NaOH as well as certain 

 other dilute alkaline solutions, have been confirmed by the careful 

 and repeated examination of specimens from widely distant points 

 in several localities. This dehiscence of the exospore wall is less 

 evident, however, in old herbarium material. 



Ellis and Everhart (6) sum up the differences between Dal- 

 dinia vernicosa and D. concentrica as follows: " This (D. verni- 

 cosa) is distinguished from D. concentrica by its shining-black 

 stroma, and the looser texture of the radiate-fibrous inner sub- 

 stance which is cut by 8-12 dark-colored, membranaceous hori- 

 zontal plates or layers. These are very noticeable in a vertical 

 section even in the young plant, while it is still covered with the 

 conidial layer and before the terminal, subglobose, ascigerous 

 stroma has begun to appear. In the mature state, the fibrous inner 

 substance and the horizontal membranes disappear to a greater 

 or less extent, and leave the stroma more or less hollow, so that 

 it may be easily crushed with the fingers, but in D. concentrica 

 the inner substance remains firm and is also of a darker color." 



Daldinia concentrica, according to Lindau (7), is of cosmo- 

 politan occurrence on dicotyledonous wood, while D. vernicosa, 

 according to Saccardo (8), is less widespread in its distribution. 

 In addition, the latter species generally occurs on burned woody 

 stems, whereas the former species does not seem to be pyroxylo- 

 philous. 



It is often very difficult to secure mature specimens of D. con- 



