PHYSARUM 51 



Nova Scotia and New York to Colorado and south, Brazil, Chile; 

 Europe, Ceylon, Malay Peninsula, Java. 



11. Physarum rubiginosum Fr. 



Symb. Gast. 21. 1817. 

 PI. IV, Figs. 51, 52. 



1825. Leangium rubiginosum Fr., Stirp. Femsj. 83. 

 1829. Physarum fulvum Fr., Syst. Myc. 3 : 143. 



Sporangia globose or cylindric, sessile or sometimes narrowed to a 

 stem-like base as if short-stipitate, 0.5-0.8 mm. in diameter, olivaceous 

 brown to reddish brown or scarlet; peridium simple, thin, rugulose 

 or plain, the calcareous scales few, or apparently included; columella 

 none; capillitium dense, the nodules rather large, angular, rusty brown; 

 spores dull violaceous, faintly warted, 9-11 ix. Plasmodium scarlet. 



A beautiful, well-marked species, evidently rare in North America. 



In the west there is a plasmodiocarpous form of the species. It has 

 the characteristic spores and capillitium but in form and habit differs 

 very decidedly. The fructification is a delicate netted plasmodiocarp, 

 the tubule about 0.5 mm. broad, bright red; peridium simple, carti- 

 laginous, dehiscent from above, and flecked with just here and there a 

 red calcareous scale. A collection from Ontario (Dearness) has spores 

 ranging from 11-12 fx, but probably belongs here. 



New Hampshire, Ontario, Iowa, Colorado; Europe. 



12. Physarum digitatum Farquh. & G. List. 



Jour. Bot. 54 : 128. 1916. 

 PL IV, Figs. 53, 54. 



1896. Physarum thejoteum Morgan, non Fr., Jour. Cin. Soc. Nat. Hist. 19 : 22. 

 1911. Physarum virescens Lister, non Ditmar, Mycetozoa ed. 2. 83. 

 1922. Physarum instratum Macbr., N. A. Slime-Moulds ed. 2. 62. 



Sporangia subglobose, obovoid or cylindrical, very small, 0.1 to 

 0.3 mm. in diameter, closely crowded on a delicate hypothallus, often 

 connate, but not superimposed; dull orange, brownish or tawny; 

 peridium thin, covered with very minute, tawny calcareous scales; 

 columella none; capillitium lax, often scanty, the nodules small, 

 yellowish or brownish, occasionally confluent; spore-mass dull vio- 

 laceous, spores pale violet, with clusters of minute warts scattered 

 over the surface, 6-7 /a. 



Not uncommon in the Mississippi valley, where it sometimes is 

 passed by the collector as an immature form of some other species. 



