DiDYMIUM 



117 



White or gray. 



Plasmodiocarps thinly effused; capil- 

 litium of simple tubes containing 

 lime crystals and forming vertical 

 columns. 

 Sporangia and slender plasmodiocarps 

 with scanty deposits of lime, de- 

 hiscing in a circumscissile manner; 

 columella absent. 

 Plasmodiocarps large, pulvinate, 1 to 

 20 mm. long, or more, dehiscing ir- 

 regularly; columella absent; capil- 

 litium an elastic network. 

 Sporangia or plasmodiocarps yellow. 



Sporangia or slender plasmodiocarps 

 with scanty, yellow lime deposits; 

 otherwise as in D. anellus. 

 Sporangia and plasmodiocarps robust 

 with orange-spotted walls; occasion- 

 ally with short, orange stalks. 

 Sporangia always stalked, gray or white except 

 occasionally in D. eximmm. 

 Sporangia disc-shaped. 



Stalk dark brown or black; spores 5-8 ju 



diam., pale and nearly smooth. 

 Stalk yellowish; spores 9-12 yu diam., dark, 

 reticulate. 

 Sporangia more or less globose and umbilicate 

 beneath. 

 Stalk long, dark; columella small, dark, 



globose. 

 Stalk long, orange; columella large, dis- 

 coidal, yellow or pale; sporangia often 

 with yellow lime crystals. 

 Stalk long, red-brown; columella subglo- 

 bose or turbinate, pale. 

 Sporangia stalked, sessile or forming plasmodio- 

 carps, white or gray. 

 Sporangia usually stalked, subglobose, umbili- 

 cate beneath; stalk short, dark; columella 

 large, dark. 

 Sporangia stalked, sessile or forming effused 

 plasmodiocarps; stalks when present, short, 

 pale; columella pale. 

 Sporangia with an outer smooth, deciduous 

 crust of lime-crystals; stalk when present 

 short, membranous, pale buff. 



14. D. Sturgisii 



15. D. anellus 



17. D. duhiiim 



1 6. D. ochroideum 



19. D.fulvum 



8. D. Claims 

 20. D. intermedium 



10. D. nigripes 



11. D. eximium 



12. D. xanthopus 



9. D. melanospermum 

 13. D. squamulosum 

 18. D. crustaceum 



