60 THE NORTH AMERICAN SLIME-MOULDS 



1829. Physar:im nutans vars. Fries, Syst. Afyc., III., pp. 128-129. 



1875. Tilmadoche imitabilis Rost., Mori., p. 129. 



1880. Tilmadoche viridis (Bull.) Sacc., Michelia, II., p. 263. 



Sporangia globose, flattened or lenticular, beneath plane or 

 concave, variously colored, yellow, greenish yellow, rusty 

 orange, stipitate, nodding; the peridium splitting irregularly 

 or reticulately ; stipe variable in length and color, through 

 various shades of red and yellow, subulate ; capillitium strongly 

 developed, concolorous with sporangium, the tubes with color- 

 less or yellow calcareous thickenings ; spores smooth, fuscous 

 or violet black, 8 /JL. 



A very handsome and rather common little species, like the 

 preceding, but generally greenish yellow in color, and occasion- 

 ally brilliantly orange without a suggestion of green. Indeed, 

 the color is so variable that some authors have been disposed to 

 discard the species entirely, inasmuch as the chief specific char- 

 acter is color. The plasmodium is pale yellow, in rotten logs, 

 stumps, etc. In the paler yellow or greenish forms the stipe is 

 more commonly black. 



This is Pliysarum luteum (Bull.) Fries, and likewise also 

 includes the three varieties, viride, aureum, coccineum, listed by 

 the same author under P. nutans, while he at the same time 

 remarks that they might with equal propriety be elsewhere 

 referred. Rostafinski considers that all the colored forms agree 

 in capillitium sufficiently to be associated under one name and 

 are in the same way unlike T. nntans. Rostafinski thinks 

 to avoid confusion by suggesting a more fitting specific 

 name, T. mutabilis, but there seems no good reason for not 

 adopting the earliest identifiable specific appellation, which in 

 this case appears to be viridis. The yellow phase is common 

 in Iowa, resembles in size, color, stipe, P. galbeum Wingate, 

 but is instantly distinguishable by the capillitium. N. A. F., 

 1213. 



Widely distributed specimens are before us from New Eng- 

 land, New York, Pennsylvania, Maryland, Ohio, Nebraska, 

 Iowa, California, Oregon, Canada, Nicaragua. 



