104 THE NORTH AMERICAN SLIME-MOULDS 



14. DIDERMA ROANENSE (Rex) Macbr. 



1893. Chondrioderma roanense Rex, Proc. Phil. Acad., p. 368. 



Sporangia scattered, discoidal, thin, flattened or slightly con- 

 vex above, plane or plano-concave below, umber brown, stipitate, 

 the outer peridium smooth, brittle, rupturing irregularly, the 

 basal fragments somewhat persistent, concrete with the inner 

 peridium, which is pure white, except near the columella, and 

 punctate; stipe short, variable, longitudinally ridged, jet black; 

 hypothallus none; columella flat, discoidal, pale ochraceous ; 

 capillitium sparse, white or colorless, composed of simple, rarely 

 forked, sinuous threads occasionally joined by lateral branches; 

 spores dark violaceous, distinctly warted, 12-14 A 1 - 



This species is readily distinguished by its color. The spo- 

 rangia, found on rotten wood, are large, i mm. +, brown, and 

 have thick, persistent walls. Dr. Rex considered that the species 

 differs from other related forms not only in color, but in the 

 well-marked discoidal columella and the jet black irregular stipe. 

 It is perhaps most nearly related to the following species. 



Tennessee. 



15. DIDERMA STELLARE (Schrad.} Persoon. 



1753. Lycopcrdon radiatnm Linn. ? Sp. PL, p. 1654. 



1797. Didyininm stellar e Schrader, Nov. Gen. PL, p. 21. 



1801. Diderma stellare (Schrad.) Persoon, Syn., p. 164. 



1875. Chondrioderma radiation (Linn.) Rost., Mon., p. 182. 



1894. Diderma radiatnm (Linn.) M.org.,Jonr. Cin. Soc., p. 66. 



Sporangia scattered, depressed-globose, sometimes also flat- 

 tened below, stipitate, smooth or slightly corrugate, ashen or 

 brownish, about i mm. in diameter, the peridium dehiscing 

 irregularly or somewhat radiately from above downwards, the 

 segments reflexed, the inner layer not distinguishable, or insepa- 

 rable ; stipe short, stout, brownish, sometimes almost lacking ; 

 hypothallus not conspicuous, but sometimes sufficient to con- 

 nect the bases of adjacent stipes ; columella large, hemispheri- 

 cal or globose, pallid or yellowish ; capillitium abundant, of 

 slender generally simple colored threads, paler at the furcate 

 tips ; spores dark violaceous, minutely roughened, S-ii p. 



