1IYMI \OGASTRACEAE 31 



dark, sordid brown to a dull or shiny black and the fibrils, so conspicuous in the fresh 

 condition, usually become so innately appressed above as to appear as though there 

 were none, while below and occasionally on the sides they remain free and conspicuous. 

 The pleasant wine-like odor is also distinctive. 



The present species seems close to R. roseolas and we were at first inclined to refer 

 our plant to that species, but upon comparing a specimen of the latter plant kindly sent 

 us by Dr. Fitzpatrick (from Dept. PL Path. Herb., N. Y. State Coll. Agric. at Cornell 

 Univ.; Whetzel, No. 598) and determined as R. roseolus by Zeller and Dodge with 

 our collections of the present plant, they were found to differ in the following ways: 

 In color the peridium of R. roseolus is citron yellow to olive brown with blackish areas 

 when dry and the fibrils are very few, innate-appressed and black when dry; the per- 

 idium of the present plant is chestnut to bay or inky black upon drying, and the fibrils 

 are very numerous and conspicuous. The peridium of the present plant is viscid when 

 fresh while in Chapel Hill collections of R. roseolus the peridium is not at all viscid. 

 In section the peridium of R. roseolus is more or less reddish brown and does not change 

 color upon the application of 7% KOH, whereas the peridium of the present plant con- 

 tains a red or orange amorphous material which changes to a purplish orange upon the 

 application of 7^ KOH. In the macro- and microscopic characters of the gleba the 

 two plants agree except for the somewhat larger spores of R. roseolus. 



In some respects the present plant resembles R. provincialis but the hairlike threads 

 making up the peridium of the latter plant and the much thinner scissile septa seem to 

 separate the former from the latter plant. 



The species differs from R. rubesccns in having a very slight though pleasant odor, 

 while the latter is very fragrant while deliquescing and retains the odor for several 

 months after drying. The almost total absence of fibrils in R. rubescens also serves to dis- 

 tinguish that plant from the present species, in which the fibrils are quite numerous and 

 conspicuous in the fresh state and are usually quite obvious in the dried condition. 

 The present plant turns black with rather inconspicuous reddish black areas on drying, 

 while R. rubescens becomes light to dark earthy tan (or dull black on crushed places) 

 on drying. In section the two plants are quite distinct: (1) the peridium in R. rubescens 

 having brownish, amorphous, crystalline material which does not change color on the 

 application of 7% KOH, the present plant having embedded in its peridium a bright 

 red or orange amorphous material which changes slowly to a purplish orange on the 

 application of 7% KOH; (2) in R. rubescens the septa are slightly scissile in the fresh 

 and very much scissile in dried plants, while in the present plant the septa are usually 

 not at all scissile in either the fresh or dried plants. 



From R. piccus which is also blackish when dry R. nigrescens easily differs in the 

 smaller, more densely packed chambers, the absence of purple color in the peridium and 

 in the more regular spores. 



Attention has already been called to the peculiarities of the basidia in the present 

 plant, a condition found in young fresh specimens of Nos. 7372 and 7569. In older 

 specimens such as Xo. 1910 no plump basidia could be found at all, whereas conditions 

 such as those represented in fig. 7 (showing collapsed basidium) are fairly common, but 

 could be made out only after crushing a section of the gleba under the cover glass. It was 

 only after studying young fresh material which showed the different stages in the 

 development of the basidia that we were able to account for the extreme difficulty in 



