PHYSARUM 87 



into patches on which the yellow lime granules are conspicuous; stipe 

 non-calcareous, pale brown or amber colored, longitudinally wrinkled, 

 about one and one-half times the diameter of the peridium; columella 

 none; hypothallus none; capillitium dense, of extremely delicate yel- 

 low threads, the nodes only here and there calcareous, the lime-knots, 

 when present, small, angular, yellow; spore-mass pale brown; spores 

 almost smooth, lilac- or violet-tinted, 7.5-10 fx. 



Distinguished among the small delicate species with which it will 

 be naturally associated, by the yellow, richly calcareous wall of the 

 globose sporangium and the almost limeless capillitium. The stipe is 

 hollow and contains irregular masses of refuse granular matter, but 

 no lime so far as we have been able to discover. P. flavicomum, to 

 which the species is related most closely, differs in having the wall 

 non-calcareous, iridescent, as well as in the color throughout; in the 

 character of the capillitium, in which lime is abundant; and in the 

 absence of refuse matter in the stem. 



Nova Scotia, Vermont, Pennsylvania, Iowa, Minnesota; Europe, 

 Ceylon. 



68. Physarum oblatum Macbr. 



Bull. Nat. Hist. S. U. Iowa 2 : 384. 1893. 

 PL VI, Figs. 120, 121. 



1896. Craterium maydis Morg., Jour. Cin. Soc. Nat. Hist. 19 : 15. 

 1909. Physarum maydis (Morg.) Torr., Fl. Myx. 193. 



Sporangia gregarious, stipitate, small, bright yellow, globose or 

 depressed-globose, rough; stipe reddish brown or fuliginous, even, 

 short, slender; hypothallus scant, black, or none; columella none; 

 threads of the capillitium hyaline or yellowish, delicate, connecting 

 the rather dense and abundant irregular yellow nodes; spore-mass 

 brownish black, spores violaceous, minutely but distinctly spinulose, 

 9-11/*. 



This species is easily recognizable by its brilliant yellow color, 

 somewhat rugose, sometimes scaly peridium, its richly calcareous 

 capillitium, also bright yellow where not weathered or faded, and its 

 dark brown, translucent, non-calcareous stem. After dehiscence, the 

 base of the peridium often persists as a cup. This circumstance, with 

 the fact that decaying maize-stalks and leaves are a favorite habitat, 

 led Professor Morgan to its description as Craterium maydis. But it is 

 doubtless a physarum, occurring on habitats of all sorts. 



Ohio to Iowa, Colorado and Washington, West Indies; Germany, 

 Rumania, Uganda, Java. 



