274 A Monorfraph of the My^rogastres. 



with granules of lime, the interuodes thin and without lime ; 

 dehiscence irregular, or by a longitudinal fissure in the plas- 

 modiocarp form. 



Physarum, Pers. 



Rost., Mon., p. 93; Cke., Brit. Myx., p. 11; Sacc, Syll., vii., 

 p. 38G ; Zopf, p. 144. 



The principal characteristic of the present genus is the 

 presence of numerous large, irregularly swollen nodes, or points 

 of junction of capillitium threads, filled with granules of lime, 

 the in te modes, or threads connecting the nodes, being thin and 

 free from lime. Physarum passes by numerous transitional 

 forms into Tilmadoche, which in the typical condition differs 

 in the much fewer and smaller lime-containing nodes of the 

 capillitium. 



Distrib. Europe ; Africa ; Himalayas ; Ceylon ; Java ; Japan ; 

 W. Australia ; N. Zealand ; Tasmania ; S. America ; W. Indies ; 

 TJ. States. Species, 70. 



A. Sporangia stvpitate. (Some species included in the 

 present section have sessile forms.) 



* Ujrisjjore loarted. 



Physarum psittacinum, Ditm. (figs. 290, 291). 



Scattered, gregarious, or fasciculate, sporangia stipitate, 

 globose, slightly rugulose, lime scanty, gree^i, often with orange 

 and deep violet tints ; stem elongated, subequal or attenuated 

 upwards, expanding at the base into a small hypothallus, longi- 

 tudinally rugulose, orangc-rcd ; capillitium abundant, consisting 

 of irregularly anastomosing, rather thin threads, connecting 

 numerous large irregular nodes filled with lime, cither colourless 

 or usually some shade of orange; columella absent; spores 

 globose, hrawnish-purplc, very minutely verructdose, 7 — 9 /x 

 diameter. 



Physarum j^sittaeinum., Ditm., Sturm, t. 62 ; Rost., Mon., p. 

 104, figs. 75, 76 ; Cooke, Brit. Myx., figs. 75, 76 ; Sacc, Syll., 

 n. 1179 (Excl. Syn. Didymium, Ravenslii, B. and C.) ; Raunk., 

 Myx. Dan., p. 74. 



