TILMADOCHE 57 



3. Tilmadoche (Fries] Rost. 



1849. Tilmadoche Fries, Sum. Veg. Sc., p. 454 



Sporangia usually simple, stalked, breaking irregularly, with- 

 out columella ; peridium very delicate, thin-walled, usually with 

 calcareous granules ; capillitium lace-like, the tubules repeatedly 

 dichotomously branched from the base, terminating by very 

 delicate points in the peridial membrane ; calcareous thicken- 

 ings not numerous, spindle-shaped, small. 



The genus Tilmadoche is by some authors united with Phy- 

 sarum, and it must be confessed that the two genera are so 

 related that it is sometimes a difficult question to say to which 

 of them a particular species is to be referred. Nevertheless 

 the group of species here presented agree among themselves in 

 such a way that they may be easily set off and limited substan- 

 tially by the lines laid down by Fries, and we believe that in so 

 doing the convenience of the student is better conserved. 



Aside from the general delicacy of structure the principal 

 distinctive feature of Tilmadoche is the capillitium. In T. 

 nutans this is shown in its typical form and is well figured 

 by Rostafinski (Man., PL VIII., 126 and 132). The threads of 

 the capillitium rise vertically from the flat, generally persistent 

 base of the peridium, and hence are in their general course 

 nearly parallel one to the other. This is in sharp contrast with 

 the netted intricate framework of Physarum. 



Key to the Species of Tilmadoche. 



A. Sporangia convolute, polymorphous . . I. T. polycephala 



B. Sporangia simple. 



a. Wall gray or whitish . . . . . 2. T. alba 



b. Wall yellow, orange, etc. . . . . 3- T. viridis 



c. Wall iridescent white, capillitium nucleate . 4. T. compacta 



I. TILMADOCHE POLYCEPHALA (Schw^) Macbr. 



PLATE VIII., Figs. 2, 2 a, 2b. 



1822. Physarum polyceph alum Schweinitz, Syn. Fung. Car., No. 382. 

 1829. Didymium polycephalum (Schw.) Fries, Syst. Myc., III., p. 122. 

 1837. Didymium polymorphicm Mont., Ann. Sci. Nat., Ser. 2, 8, p. 361. 



