Diderma spumarioides

Diderma spumarioides (Fries) Fries, Syst. Myc. 3: 104. 1829
Didymium Spumarioides^ Fries, Symb. Gast. 20. 1818.
Physarum stromateum Link, Handb. 3: 409. 1833.
Carcerina Spumarioides Fries, Summa Veg. Scand. 451. 1849.
Chondrioderma spumarioides Rost.; Fuckel, Jahrb. Nass. Ver. Nat. 27-28: 74. 1873.
Chondrioderma stromateum Rost. Monog. Append. 18. 1876.
Chondrioderma virgineum Massee, Monog. 207. 1892.
Diderma stromateum Morgan, Jour. Cine. Soc. Nat. Hist. 16: 152. 1894.
Diderma cinereum Morgan, Jour. Cine. Soc. Nat. Hist. 16: 154. 1894.
Sporangia sessile, white, globose, 0.4-0.8 mm. in diameter, gregarious or more commonly crowded and distorted by pressure, smooth or rugose, sometimes, especially in tropical collections, areolate; peridium double, the outer layer densely calcareous, fragile, closely applied to the membranous inner layer; columella convex or hemispheric, rarely cylindric or digitate, or forming free, fusiform, calcareous accretions mingled with the capillitium, white or pale fleshcolored; capillitium usually abundant, the threads purple-brown, branching and anastomosing, the tips paler; hypothallus white, usually abundant, the sporangia more or less imbedded in it; spores black in^nass, dark violet-brown by transmitted light, distinctly but rather sparsely warted, 8-11 n in diameter; Plasmodium white.
Type locality: Europe. Habitat: Dead leaves.
Distribution: Throughout North America; cosmopolitan.