PHYSARUM 49 



A very distinct species not likely to be confused with anything else. 

 In description, so far as concerns external characters, it suggests 

 Cienkowskia reticulata, but lacks the orange and red colors. The two 

 forms are not at all alike when placed side by side. For details as to 

 the difference, see the description of the species last mentioned. 



In 1805, Albertini and Schweinitz (Consp. Fung. 90) described as 

 Physarum reticulatum a European form which became the basis of 

 Rostafinski's genus Cienkowskia. Later, in 1829, Schweinitz collected 

 in America a physarum-like specimen which he took to be the same 

 thing, and accordingly placed it in his herbarium under this name, and 

 listed it in his 1832 paper as No. 2295. Rostafinski further renamed 

 another Schweinitzian species, Fuligo muscorum, calling it (Mon. Ill) 

 Physarum gyrosum. Wingate and Rex apply in Ellis, N. A. F. 1396, 

 this latter name to No. 2295 of Schweinitz. Such a reference is a mis- 

 take, judging from Rostafinski's descriptions and from the descrip- 

 tions and figure of Albertini and Schweinitz (Consp. Fung. 86), and 

 by the testimony of Lister. 



Eastern United States to Iowa and Nebraska, not rare; Japan. 



8. Physarum aureum Brandza, non Pers. 1794 



BuU. Soc. Myc. Fr. 44 : 261. 1929. 



Sporangia solitary or in small groups, sessile, 0.4-0.6 mm. in di- 

 ameter or forming elongated, sinuous plasmodiocarps, 2-12 mm. long 

 by 0.4-0.6 mm. wide, bright yellow; peridium rugulose, pelliculose, 

 transparent yellow, encrusted with very minute yellow calcareous 

 granules clustered in small groups; columella lacking; capillitium well 

 developed, long-persistent, with firm, bright yellow calcareous nodes, 

 angular and of unequal sizes, ranging from 10-25 n, composed of very 

 minute calcareous granules similar to those on the peridium and not 

 breaking up in water; connecting threads numerous, hyaline, branched; 

 spores pale violaceous brown, minutely echinulate, 9-12 /jl. Plasmodium 

 bright yellow. 



South Carolina, New York; Rumania. 



9. Physarum virescens Ditmar 



in Sturm, Deutsch. Fl. Pilze 1 : 123. 1817. 

 PI. Ill, Figs. 49, 50. 



1818. Physarum thejoteum Fr., Symb. Gast. 21. 



1832. Physarum ccespitosum Schw., Trans. Am. Phil. Soc. II. 4 : 258. 



1873. Didymium nectriceforme Berk. & Curt., Grev. 2 : 65. 



1876. Physarum ditmari Rost., Mon. App. 8. 



1877. Didymium sinapinum Cooke, Myx. Gt. Brit. 33. 



