DiDERMA 101 



This species is more common than D. niveum, and Hke it is 

 confined to the more western part of North America. It is dis- 

 tinguished from D. niveum by the paler, flesh-colored inner wall, 

 and the spores, which are usually larger, darker, and more 

 coarsely marked. The spores of American specimens are not as 

 dark nor as rough as those of European forms, generally. The 

 columella is more prominent than that of D. niveum. The lime in 

 the sporangial wall is sometimes in the form of vitreous plates 

 which makes the sporangia appear gray. 



10. Diderma testaceum (Schrad.) Pers. Syn. Meth. Fung. 167. 

 1801. 



Didymium testaceum Schrad. Nov, Gen. PI. 25. 1797, 



Plasmodium yellowish buff (Torrend). Sporangia gregarious, 

 subglobose, 0.6 to 0.8 mm. diam., sessile, depressed on a broad 

 base, sometimes confluent, smooth, flesh-colored or pale pinkish, 

 often faded to white; sporangial wall of two layers, the outer 

 thin, brittle, eggshell-like, composed of globular lime-granules, 

 separating freely from the more persistent, pinkish gray, mem- 

 branous, inner layer. Columella large, convex or hemispherical, 

 together with the base of the sporangium flesh-colored or reddish 

 brown. Capillitium consisting of delicate, pale purplish, branch- 

 ing, flexuose threads. Spores pale violet-brown, almost smooth, 

 7-10 M diam. 



Type locality: Europe. 



Habitat: On dead leaves, mosses, etc., in wet places. 



Distribution: Common in North America. 



Illustration: Lister, Mycetozoa ed. 3. pi. 87, figs. a-c. 



Appearing in June, and repeatedly thereafter during the sum- 

 mer and autumn, in wet bogs and swamps, it is often in great 

 abundance. From other similar forms it is distinguished by its 

 color, the large, often dark columella, the depressed shape, and 

 the scattered habit. The sporangia are often white. 



11. Diderma simplex (Schroet.) Lister, Mycetozoa ed. 2, 107, 

 1911. 



Chondrioderma simplex Schroet. in Cohn, Krypt. Fl. Schles. 3 (1): 123, 1885, 



Plasmodium orange-brown (Lister). Sporangia sessile, scat- 

 tered, crowded, in small clusters, or heaped, 0.4 to 1 mm. diam., 

 subglobose, pulvinate, or depressed, or forming short, curved, or 



