[VOL. 4 



238 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



of Merulius have the hymenium even in some small, im- 

 mature fructifications and with a broad, marginal, even 

 region in larger ones, it is necessary to see fully mature and 

 well-developed fructifications to be certain that a collection 

 of one of these connecting species is a Coniophora rather 

 than a Merulius. The absence of a definite statement by 

 De Candolle on this point led Fries to question the generic 

 position of Coniophora memhranacea DC. 



The dark color of spores in the mass in spore collections 

 is a decisive character for distinguishing some species of 

 Coniophora from Corticium and Peniophora. In working 

 with dried herbarium specimens which lack spore collections, 

 if the natural color pigment of sections is destroyed and 

 bleached by KHO solution, some sections should be treated 

 with lactic acid to determine whether the spores are hyaline 

 or pigmented like the hyphae. In my experience lactic acid 

 does not change a common, ochraceous, fungous pigment 

 which is dissolved and bleached by KHO solution. 



All our species of Coniophora are saprophytic on wood and 

 cause dry rot of the wood. The most of these species are rare 

 or have been collected infrequently, and record is lacking of 

 the extent of rot which they cause. Coniophora cerehella, 

 more commonly called C. puteana, is conunon and widely dis- 

 tributed throughout the northern United States and Canada. 

 It is very destructive to structural timber of coniferous 

 species if poorly seasoned or if used in moist places where 

 there is a poor circulation of air or if used in contact with 

 the ground without previous treatment with a wood preser- 

 vative. In the United States this species seems to be as im- 

 portant an agent of timber decay as the Merulius lacrymans 

 group of species is in Europe. While Coniophora cerehella 

 attacks chiefly coniferous timber of buildings, bridges, docks, 

 etc., in forests it is often found on logs of deciduous species. 

 C. arida is another species of this genus so common as to be 

 of economic importance. This species has been collected but 

 rarely on other than a coniferous substratum; it ranges 

 rather farther south than the general range of C cerehella 

 but has not been received from farther south than Louisiana. 



