physarum] physaraceae 51 



globose, flattened beneath, erect or inclined, purple, 0-4 to 

 - 5 mm. diam., gregarious ; sporangium- wall membranous, 

 pale purple, with scattered clusters of large purple globular 

 lime-granules (1 // diam.). Stalk purple, subulate, OS to 1 mm. 

 long, brittle, containing lime. Columella small, convex, or 

 none. Capillitium a close network of delicate purplish threads, 

 broader and more expanded at the axils below ; lime-knots 

 numerous, small, roundish, filled with purple globular lime- 

 granules. Spores pale dull red, almost smooth, 7 to 8 /x diam. — 

 Rost. Mon., p. 105, fig. 84 ; Macbr. N. Am. Slime-Moulds, 49. 

 Physarum atrorubrum Peck, in Rep. New York Mus., xxxi. 

 40 (1879) ; Mass. Mon.. 294. 



PI. 19. — a. sporangia ; b. capillitium and spores ; c. spore ; (Ceylon). 



Hob. On dead wood.— Ceylon (B.M. 2108) ; Ohio (B.M. 1207) ; 

 Iowa (B.M. 1013) ; South Carolina (B.M. 412) ; Philadelphia (B.M. 

 1809). 



10. P. citrinum Schumacher Enum. PL Saell., ii. 201 (1803). 

 Plasmodium bright yellow. Total height 0-8 to 2 mm. 

 Sporangia globose, rugose, stalked, rarely nearly sessile, 

 erect, yellow to yellowish -grey, 0-4 to 0*7 mm. diam. ; 

 sporangium-wall membranous with included clusters of yellow 

 lime granules. Stalk golden - yellow, opaque with dense 

 deposits of lime, stout, somewhat furrowed, 0- 1 to 0*6 mm. long, 

 chalky in section, often rising from a vein-like hypothallus. 

 Columella short, conical or obtuse. Capillitium a somewhat 

 close network of hyaline rigid threads with flat expansions 

 at the axils, persistent after the dispersion of the spores ; 

 lime-knots yellow, numerous, varying in shape and size, 

 usually rounded, seldom developed at the axils of the branches. 

 Spores violet-brown, almost smooth, 7 to 10 fi diam. — Fr. 

 Symb. Gast., 22 (1818) ; Macbr. N. Am. Slime-Moulds, 56. 

 P. compactum Ehrenb. Syl. Ber., 21 (1818). P. Schumacheri 

 Spreng. Sys. Veg., iv. 528 (1827) ; Rost. Mon., p. 98 ; Mass. 

 Mon., 275. P. aureum (3 chrysopus Lev. in Ann. Sc. Nat., 

 ser. 3, v. 166 (1846). P. Schroeteri Rost. I.e., 419 ? P. Leveillei 

 Rost. Mon., App. p. 7 (1876), in part ; Mass. I.e., 296. 



PI. 20. — a. sporangia ; 6. capillitium and spores ; c. spore ; (Bedfordshire). 

 Pvostafinski describes P. Leveillei as being closely allied to the 

 present species, but having larger spores, measuring 10 to 11 /x instead 

 of 7 to 8 /a. His type of P. Leveillei a from Freiburg, leg. de Bary 

 (Strassb. Herb.), is P. citrinum with large yellow sporangia and spores 

 8 fi diam. ; the gathering from Venezuela (K. 1261) quoted by him as 

 P. Leveillei fi auripes is P. citrinum with rather long stalks, and spores 

 measuring 10 fi ; his P. Leveillei a from Chili (ex herb. Gay, Paris Herb.) 

 is typical P. viride. 



Hob. On dead wood and moss. — Hertfordshire (B.M. 1208) ; 

 Falmouth (B.M. 2110); Aberdeen (B.M. 2109); Switzerland (B.M. 

 2111); Austria (B.M. 2112); Germany (B.M. 1209); Venezuela 

 (K. 1261). 



