CRATERIUM 73 



6. Craterium Trentepohl. 



1797. Craterium Trentepohl, Roth, Catal., I., p. 224. 



Sporangia more or less distinctly cyathiform, stipitate, the 

 peridium generally plainly of two layers or even of three, 

 opening at the top by circumscission more or less definite, or 

 by a distinct lid, the upper part calcareous often to a marked 

 degree, the lower, cartilaginous, long persistent as a vasiform 

 cup containing the capillitium and spores, the calcareous nodes 

 aggregating more or less to form a pseudo-columella. 



This genus is distinguished from Pliysarum and BadJiamia 

 chiefly by the form of the sporangia and the method of dehis- 

 cence. The capillitium is in some specimens, particularly, of 

 the Physarum type ; in others, like that of BadJiamia. There 

 are accordingly species that receive at the hands of different 

 authors diverse generic reference as one feature or another in 

 the structure is emphasized in the different cases. It is granted 

 that it is hard to draw the line sometimes between forms in 

 which the dehiscence is irregularly circumscissile and those in 

 which the wall breaks without any irregularity whatever, since, 

 in all, the breaking up of the peridium usually begins at the top. 

 Species here included will, however, offer little ambiguity. 



Key to the Species of Craterium. 



A. Dehiscence circumscissile or by the breaking up of the upper wall of 



the sporangium. 



a. Sporangia violet or purple . . . 3. C. rubescens 



b. Sporangia yellow. 



1. Sporangia vasiform .... I. C. aureum 



2. Sporangia globose . . . . 2. C. maydis 



c. Sporangia white-capped. 



1 . Sporangia obovoid or globoid . 4. C. leucocephalum 



2. Sporangia cylindric, elongate . . 5. C. minimum 



B. Dehiscence by a distinct lid. 



a. Capillitium pale brown 6. C. concinnnm 



b. Capillitium white 7. C. minutum 



i. CRATERIUM AUREUM (Scfium.') Rost. 



1803. Trichia aurea Schum., Emim. PI. Saell., II., p. 207. 



