Physarum pusillum

Fungus / parasite
Acremonium anamorph of Nectria candicans parasitises sporangium of Physarum pusillum

Physarum pusillum (Berk. & Curt.) G. Lister in Lister,
Mycet. ed. 2. 64. 1911.
Didymium pusillum Berk. & Curt.; Berk. Grevillea 2: 53. 1873.
Badhamia nodulosa Massee, Jour. Myc. 5: 186. 1889.
PhysarUm calidris Lister, Jour. Bot. 29: 258. 1891.
Craterium nodulosum Morgan, Jour. Cine. Soc. Nat. Hist. 19: 15. 1896.
Physarum gravidum Morgan, Jour. Cine. Soc. Nat. Hist. 19: 24. 1896.
Physarum nodulosum Macbr. N. Am. Slime-Moulds 51. 1899.
Sporangia stipitate, gregarious, globose, small, 0.4-0.6 mm. in diameter, grayish-white with a brown base ; peridium thin, rugose, more or less incrusted with lime, breaking up irregularly; stalk slender, exceeding the sporangium, cylindric or somewhat attenuate above, rugose, bright brown, merging into the shallow, cup-like base of the sporangium; columella none; capillitium variable, the nodes white, angular and scattered or badhamioid; spores black in mass, pale lilaceous-brown by transmitted light, minutely warted, 10-12 fx in diameter; Plasmodium watery-white.
TypB locality: Aiken, South Carolina.
Habitat: Dead leaves and herbaceous litter, often on compost.
Distribution: Throughout temperate and tropical North America; cosmopolitan.