DiDERMA 105 



Virginia. Var. nivale, found in the Swiss Alps, is unknown from 

 North America. 



15. Diderma floriforme (Bull.) Pers. Neues Mag. Bot. 1: 89. 

 1794. 



Sphaerocarpus floriformis Bull. Herb, Fr. pi. 371. 1787; Bull. Champ. 142. 

 1791. 



Plasmodium grayish white (Lister). Total height 1 to 2 mm. 

 Sporangia crowded, often forming large colonies, globose, stalked, 

 erect, smooth, about 0.8 mm. diam., varying from grayish white 

 to ochraceous brown; sporangial wall splitting into revolute 

 petaloid lobes, pale brown on the inner side, cartilaginous, opaque, 

 with a closely adhering, membranous inner layer. Stalks cylin- 

 drical, furrowed, 0.5 to 1 mm. long, 0.15 mm. thick, ochraceous 

 brown, often connected below by a well-developed hypothallus. 

 Columella usually clavate, buff to brownish, densely calcareous. 

 Capillitium consisting of slender, sparingly branched threads, 

 with scattered bead-like thickenings, thicker and anastomosing 

 at the base, dark violet-brown. Spores reddish violet-brown, 

 paler on one side, marked with scattered obtuse warts, 8-11 tx 

 diam. (Plate 9, fig. 4.) 



Type locality: France. 



Habitat: On decaying wood. 



Distribution: Common in eastern North America, and 

 probably elsewhere. 



Illustration: Lister, Mycetozoa ed. 3. pi. 92. 



The large colonies appear about the middle of August on very 

 rotten wood. The spores, with strong, scattered warts, distin- 

 guish the species from all forms of D. radiatum, or the columella, 

 when clavate, is usually sufficient. Limeless developments, 

 purple-brown in color and on dark stalks, are occasionally found. 

 The lime is sometimes in the form of vitreous discs or plates, a 

 feature not unusual in other species of Diderma. 



16. Diderma radiatum (L.) Morg. Jour. Cin. Soc. Nat. Hist. 16: 

 151. 1894. 



Lycoperdon radiatum L. Sp. Plant, ed. 2. 1654, 1763. 



Plasmodium white or pale yellow (Lister). Sporangia scat- 

 tered or crowded, subglobose or hemispherical and depressed, 

 flattened or umbilicate beneath, stalked or sessile, smooth or 

 somewhat wrinkled and rimose, 0.5 to 1.2 mm. diam., pale gray, 



