84 THE MYXOMYCETES 



62. Physarum carneum G. List. & Sturgis 



Jour. Bot. 48 : 63. 1910. 



Sporangia gregarious, stipitate, rarely sessile or forming short plas- 

 modiocarps, subglobose, 0.5 mm. in diameter, ochraceous yellow above, 

 flesh colored below; peridium membranous, pale yellow, lime granules 

 evenly distributed; stipe short, translucent, pinkish flesh colored; 

 capillitium dense, nodules white; spores purplish brown, spinulose, 

 8-9 ul. 



Differs from P. citrinellum in the membranous peridium, flesh colored 

 stalks and smaller spores. 



Colorado, Montana, Washington, Oregon; Europe. 



63. Physarum flavicomum Berk. 



Hooker Jour. Bot. 4 : 66. 1845. 

 PI. VI, Figs. Ill, 112, 113. 



1873. Physarum cupripes Berk. & Rav., Grev. 2 : 65. 

 1875. Physarum berkeleyi Rost., Mon. 105, in part. 

 1892. Didymium flavicomum (Berk.) Massee, Mon. 242. 



Sporangia gregarious, spherical or lenticular, small, 0.3-0.5 mm. in 

 diameter, at first fuliginous throughout, stipitate; peridium thin, 

 destitute of lime, iridescent, breaking up and deciduous in patches, 

 except at the base; stipe twice the diameter of the peridium or more, 

 golden or brown, fluted, often twisted, not hollow, tapering upward 

 from a small but distinct, radiant hypothallus; columella none; cap- 

 illitium dense, persistent, the nodes frequently calcareous, elongate 

 and vertical, especially below, yellow; spore-mass brown; spores by 

 transmitted light bright violaceous brown, faintly papillose, 9-10 /jl. 



This species is instantly distinguishable from all cognate forms by 

 its peculiar sooty color. Not less is the species structurally marked 

 by its capillitium. The latter below is exactly as in the species formerly 

 referred to Tilmadoche. Indeed, the present species unites characters 

 supposed to distinguish Physarum from Tilmadoche, and thus justifies 

 those who bring all the species of both genera together under one 

 generic name. In any case the species is by its capillitium entirely 

 distinct from P. galbeum, as well as by the structure of the stipe and 

 the peridial surface. The Plasmodium, at first watery, emerges from 

 decayed elm logs and soon takes on a peculiar greenish tint preserved 

 somewhat in the mature fruit. 



Rostafinski (Monograph 105, 106), rejects Berkeley's specific name, 

 flavicomum, because it refers to the somewhat indefinite color. As 



