PHYSARUM 83 



mass black; spores violaceous brown by transmitted light, strongly 

 spinulose, 10-12.5 fx. Plasmodium greenish. 



A very distinct and handsome species. Easily recognizable at sight 

 by its large, globose, almost sessile and yet distinctly stalked sporangia. 

 The color to the naked eye is pale ochraceous or buff. Only under a 

 moderate magnification do the citrine tints come out. 



In the Twenty-second N. Y. Report Peck incorrectly referred 

 this species to Physarum citrinum Schum. On the appearance of 

 Rostafinski's Monograph, Peck changed the name to P. citrinellum. 

 Under the last name the species has been generally recognized in the 

 United States and distributed. 



Eastern United States, Oregon; Germany, Rumania, Japan. 



61. Physarum variabile Rex 



Proc. Acad. Nat. Sc. Phila. 1893 : 371. 



1925. Physarum sulphureum Alb. & Schw. ex Lister, Mycetozoa ed. 3. 26, 

 in part. 



Sporangia scattered, stipitate, substipitate or sessile, about 1 mm. 

 high, regularly or irregularly globose, ellipsoidal, obovate or cylindric- 

 clavate in shape; sporangium wall sometimes apparently thick, of a 

 dingy yellow or brownish ochre color, slightly rugulose on the surface, 

 crustaceous, brittle, rupturing irregularly, sometimes thin, translucent, 

 covered externally with flat circular calcareous masses falling away in 

 patches; stipes nearly equal, occasionally much expanded at the base, 

 rough, longitudinally rugose, variable in size, sometimes one-third of 

 a millimeter high, sometimes a mere plasmodic thickening of the base 

 of the sporangium ; color of stipes varying from a yellowish white to a 

 dull brownish gray; capillitium a small-meshed network of delicate 

 colorless tubules with large, many-angled, rounded masses of white, 

 or rarely yellowish white lime granules at the nodes; no true colu- 

 mella, but often a central irregular mass of white lime granules; spores 

 dark violet-brown, verruculose, 9-10 fx. 



In the English monograph this is included in P. sulphureum; Brandza 

 would recognize it as a variety, differing mainly in shape from typical 

 forms of that species; Rex thought the color difference significant. 

 What were previously regarded as sessile forms of Rex's species are 

 now commonly referred to P. sessile Brandza, but Mr. Hagelstein is 

 of the opinion that there are sessile forms of P. variabile. In view of 

 the uncertainty, the species may be maintained pending further 

 information. 



Rare. Pennsylvania, New York, Venezuela; Rumania. 



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