physartjm] physaraceae 55 



16. P. psittacinum Ditm. in Sturm Deutsch. Fl., Pilze, 

 125, t. 62 (1817). Plasmodium orange. Total height 1 mm. 

 Sporangia stalked, globose or somewhat depressed, gregari- 

 ous, 0-5 to - 8 mm. diam., purplish-blue mottled with red, 

 iridescent ; sporangium-wall hyaline, delicately membranous, 

 sprinkled with orange spots of thicker more or less granular 

 substance. Stalk erect or curved, furrowed, vermilion or 

 orange-red, intense clear orange in mountings in glycerine, 

 without deposits of lime, rising from a well-developed 

 hypothallus of the same colour. Columella none. Capillitium 

 a close network of flat arching colourless or yellowish threads, 

 broad at the axils ; lime-knots numerous, varying in size, 

 sharply angular, often branching, or confluent in the centre 

 of the sporangium, bright orange, obscurely granular or 

 translucent. Spores greyish-violet, nearly smooth, 7 to 8 ft 

 diam.— Post. Mon., p. 104, figs. 75, 76 ; Mass. Mon., 274 ; 

 Macbr. N. Am. Slime-Moulds, 51. P. Carlylei Mass. I.e., 293. 



Var. fulvum Lister : stalk and base of sporangium- 

 wall fulvous- yellow instead of vermilion. — Lister in Journ. 

 Bot. xliv. 228 (1906). 



PL 29. — a. sporangia (Lyme Regis) ; b. sporangia of var. fulvum (Ceylon) ; e . 

 capillitium and spores, with fragment of sporangium- wall showing crystalline discs ; 

 d. spore. 



In glycerine mountings of this species flattened disc-shaped 

 crystalline bodias with radiating structure are usually seen imbedded 

 in the sporangium-wall, as in P. virescens and P. dictyospermum. The 

 type specimen of P. Carlylei Mass. from Carlisle (K. 68) is normal 

 P. psittacinum. 



Hab. On dead wood. — Lyme Regis, Dorset (B.M. 1217) ; Cornwall 

 (B.M. 2123) ; Wales (B.M. 2125) ; Dublin (2124) ; Berlin (B.M. 

 2126) ; Sweden (B.M. 2127) ; Austria (B.M. 2128) ; Switzerland (Herb. 

 Zurich) ; Massachusetts (B.M. 2129) ; New York (B.M. 1894) : var. 

 fulvum— Ceylon (B.M. 2130) ; Japan (B.M. 1994). 



17. P. dictyospermum Lister in Journ. Bot., xliii. 112 

 (1905). Plasmodium ? Sporangia subglobose, shortly stalked, 

 erect, scattered, 0*5 to - 6 mm. diam., dull orange or 

 dark olive-brown, glossy ; sporangium- wall membranous, 

 rather firm, orange. Stalk 0*1 to 0*5 mm. high, black, 

 enclosing dark refuse matter, or sometimes pale yellow above 

 from superficial deposits of lime-granules. Columella black, 

 conical or hemispherical, short or one-third the height of the 

 sporangium. Capillitium an abundant persistent network 

 of slender colourless threads, with small fusiform orange-red 

 lime-knots. Spores pale purplish-grey, 10 to 11 /x diam., 

 closely reticulated with narrow dark bands ; these form a net 

 with five or six meshes in a row on one side of the spore ; 

 on the other side the meshes are more faint and irregular. — 

 Torrend Fl. Myx. ; 195. 



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