44 ENDOSPOREAE [PHYSARUM 



Stalk yellowish or dark, slender ; sporangia com- 

 pressed and lobed, often clustered (smaller than 

 P. compressum, to which it is very nearly allied). 



39. P. reniforme 



B. Sporangia sessile, never stalked — (for occasional sessile 

 forms, see 4, 8, 13, 24, 25, 29, 31, 33, 34, 37). 



a. Lime-knots white — 



a. Sporangium -wall single — 



Sporangia subglobose or forming plasmodiocarps, 

 white or grey; spores pale brownish- violet, 7-8, a 

 diam. 40. P. cinereum 



Sporangia subglobose, heaped, the walls with scanty 

 or no lime deposits, spores brownish- violet. 10-11 p 

 diam. 41. P. atrum 



Sporangia subglobose or forming plasmodiocarps ; 

 white or grey, spores dark violet-brown, 9—11 //, 

 diam. 42. P. vemum 



Sporangia much compressed, forming rosettes or net- 

 like plasmodiocarps ; lime-knots fusiform. 



43. P. gyrosum 



Sporangia crowded, chestnut-brown. 



44. P. Gulielmae 



b. Sporangium- wall double — 



* Sporangia scattered, forming plasmodiocarps — 



Plasmodiocarps sinuous, compressed, white ; spores 

 marked with strong ridges and spines, brownish 

 purple. 45. P. echinosporum 



Plasmodiocarps sinuous, compressed, white or buff; 

 inner wall fragile, colourless ; spores purple- 

 brown, spinulose. 46. P. sinuosum 



Plasmodiocarps sinuous, buff or brown, marked with 

 pale lines of dehiscence ; spores pale brownish 

 violet, nearly smooth. 47. P. bogoriense 



Plasmodiocarps white, usually compressed ; inner 

 wall purplish, sub-persistent ; spores dark purplish 

 brown, spinulose. 48. P. bitectum 



** Sporangia crowded, reniform or subglobose — 



Sporangia white, subglobose, outer wall shell-like. 



49. P. testaceum 



Sporangia yellow ; spores dark, rough, 10-14 jx. 



50. P. contextum 



