DiDERMA 



93 



Sporangia subglobose, the single wall wrinkled 

 with many reticulations; stalk slender, black. 

 Sporangia flattened, disc-shaped, mottled red- 

 brown; stalk black, slender or stout, short. 

 Sporangia sessile. 



Sporangia subglobose, ochraceous or pinkish; 

 capillitium usually colorless; spores dark, 

 10-16 M. 

 Sporangia or plasmodiocarps ochraceous; capil- 

 litium purplish brown; spores purplish gray, 

 9-11 M. 

 Sporangia stalked or sessile, dehiscing by petaloid 

 lobes. (See also 15.) 

 Sporangial wall enclosing a middle layer of 

 coarse, irregular lime crystals; sporangia red- 

 dish brown; columella minute or absent. 

 Sporangial wall without an inner crystalline 

 layer. 

 Sporangia gray or brown, often mottled; 

 columella usually prominent; stalk stout, 

 ochraceous; spores minutely spinulose. 

 Sporangia brown, usually sessile, the wall 

 marked with close, radiating lines; colu- 

 mella pale, subglobose, prominent. 



19. D. rugosum 

 17. D. roanense 



12. D. Sauteri 



13. D. ochraceu 



m 



14. D. Trevelyani 



16. D. radiatum 



18. D. aster oides 



1. Diderma montanum Meylan, Ann. Conserv. Bot. Geneve 16: 

 311. 1913. (N. Y. B. G. no. 7063, authentic material.) 



Chondrioderma montanum Meylan, Bull. Soc. Bot. Geneve II. 2: 262. 1910. 

 Diderma cor-rubrum Macbr. N. A. Slime-Moulds ed. 2. 140. 1922. 



Plasmodium white or pale yellow? (Lister). Sporangia scat- 

 tered or in small groups, subglobose, 0.6 to 0.8 mm. diam., flat- 

 tened or umbilicate beneath, white or pinkish, smooth or some- 

 what wrinkled, stalked; sporangial wall of two often separating 

 layers, the outer densely charged with lime-granules, the inner 

 membranous, reddish brown throughout or toward the base. 

 Stalk pale or bright yellow-brown, slender or stout, enclosing 

 white lime-granules, 0.1 to 0.8 mm. high. Columella usually 

 globose, small, brownish red, sometimes stalked. Capillitium 

 consisting of slender purplish or hyaline threads, branching and 

 anastomosing towards the ends. Spores pale purplish brown, 

 faintly spinulose, 8-10 n diam. 



Var. album (Torrend) G. Lister, Mycetozoa ed. 3. 84. 1925. 

 Chondrioderma radiatum (L.) Rost. var. album Torrend, Fl. Myx. 168. 1909. 



