PHYSARUM 69 



white, with minute, white, round or rounded nodes, in the center a 

 conspicuous mass of lime forming a shining ball, not part of the stipe 

 although sometimes produced toward it; spore-mass black; spores 

 brown-violet, delicately spinulose, 6-7 p. 



This species most nearly resembles in appearance and habit of growth 

 P. globuliferum Pers., but may be distinguished from it by the absence 

 of a columella, by the central ball of lime, and the very small rounded 

 lime granules in the meshes of the capillitium. Exceptionally the lime 

 granules of the sporangium wall are sparse or absent entirely, in which 

 case the wall has a silvery or coppery metallic luster. 



Var. robustum G. Lister (Jour. Bot. 64 : 226, 1926) is larger, with a 

 very short stipe and a blue or coppery, iridescent peridium. 



New York, Pennsylvania, Maryland, Wisconsin, Iowa, Nicaragua; 

 Europe, South Africa, Japan ; the tropics generally. 



41. Physarum wingatense Macbr. 



N. A. Slime-Moulds ed. 2. 72. 1922. 

 PI. V, Figs. 91, 92. 



1876. Tiltnadoche columbina Rost., Mon. App. 13. 



1889. Tiltnadoche compacta Wing., Proc. Acad. Nat. Sc. Phila. 48. 



1892. Didymium barteri Massee, Mon. 231. 



1892. Lepidoderma stellatum Massee, Mon. 252. 



1894. Physarum compactum (Wing.) List., Mycetozoa 44. 



1916. Physarum columbinum (Rost.) Sturgis, Mycologia 8 : 200. 



Sporangia gregarious or somewhat crowded, stipitate, erect or 

 cernuous, gray, brownish gray or bronze, globose; peridium thin, 

 metallic brown or bronze in color, splitting at maturity in floriform 

 manner into six to twelve segments; stipe limy, white or yellowish, 

 often shading to black or fuscous below, rather long, tapering upward; 

 hypothallus none; columella none; capillitium extremely delicate, 

 white or colorless, usually radiating from a central lime-mass or nucleus, 

 and with ordinary nodules small and few, fusiform; spore-mass brown; 

 spores by transmitted light violet-brown, delicately warted, 7-9 /z. 

 Plasmodium light gray. 



This species is well marked by several characteristics; the brilliant 

 wall of the peridium, white-flecked and laciniate, the delicate didym- 

 ium-like capillitium running from center to peridium, and especially 

 the peculiar aggregation of Ume at the center of the sporangium, like 

 nothing else except a similar structure found in Physarum nucleatum 

 Rex. The variations affect the stipe and the distribution of the capil- 

 litial lime. Some eastern specimens show stipes black below; specimens 

 from Ohio and Nicaragua show stipes milk-white throughout. As to 



