Enerthenema 169 



Genus 18. ENERTHENEMA Bowman, Trans. Linn. Soc. 

 16: 152. 1830. 



Sporangia stalked- columella extending to the summit of the 

 sporangium and expanding there as a dark, shining disc; capil- 

 litium springing from the disc and extending downward. 



Type species: Enerthenema elegans Bowman. 



Spores free. 



Sporangia small, purplish brown or purplish black; 

 apical disc small; spores minutely spinulose, 10- 

 \2 IX diam. 1. E. papillatum 



Sporangia large, deep black; apical disc large; 



spores darker, coarsely spinose, 12-14 ^ diam. 2. E. melanospermum 



Spores in clusters. 3. E. Berkeleyanum 



1. Enerthenema papillatum (Pers.) Rost. Mon. App. 28. 1876. 



Stemonitis papiUata Pers. Neues Mag. Bot. 1: 90. 1794. 

 Enerthenema elegans Bowman, Trans. Linn. Soc. 16: 152. 1830. 



Plasmodium watery white (Lister). Total height 1 to 1.5 

 mm. Sporangia gregarious, stalked, globose, 0.5 to 0.7 mm. 

 diam., purplish brown or purplish black, crowned with the small 

 expanded apex of the columella; sporangial wall evanescent. 

 Stalk cylindrical or tapering, black. Columella slender, cylin- 

 drical, from a conical base, traversing the sporangium and ex- 

 panding on the surface into a black, membranous disc 0.1 to 0.2 

 mm. diam. Threads of the capillitium spreading downward 

 from the expanded apex of the columella, long, slender, black, 

 straight or flexuose, sparingly branched. Spores purplish brown 

 or purplish gray, spinulose, 10-12 /x diam. 



Type locality: Europe. 



Habitat: On dead wood. 



Distribution: Throughout the United States and Canada, 

 not uncommon. 



Illustration: Lister, Mycetozoa ed. 3. pi. 128, figs. a-e. 



2. Enerthenema melanospermum Macbr. & Martin; Martin, 

 Jour. Wash. Acad. Sc. 22:91. 1932. {N.Y .B.G. nos.7228, 

 12624, type material.) 



Plasmodium? This species is similar to E. papillatum but 

 more robust, deep black in color, with larger sporangia and a 

 larger apical disc. The spores are darker, strongly spinose, and 

 larger, 12-14 fx diam. 



