

physarum] physaraceae 75 



42. P. vernum Somin. in litt. ex Fr. Syst. Myc, iii. 146 

 (1829). Plasmodium white. Sporangia sessile, subglobose 

 or forming short or elongated often crowded plasmodiocarps, 

 greyish-white, 05 to 1 mm. diam., often several millimeters 

 in length, rugulose ; sporangium- wall membranous usually 

 densely charged with lime-granules, sometimes iridescent 

 from absence of lime. Capillitium consisting of short hyaline 

 threads connecting numerous angular branching white lime- 

 knots, that often unite in the centre to form a pseudo-colu- 

 mella. Spores purplish-brown, spinulose, 9 to 12 fi diam. — 

 Lister in Journ. Bot., xxxv. 210. Badhamia vema Rost. 

 Mon., p. 145 (1875), in part. 



PI. 48. — a. sporangia (Arolla, Switzerland) ; b. capillitium and spores ; e. spore. 



This species differs from P. cinereum to which it is very closely allied 

 by the darker and visually larger spores. It is abundant in this country 

 on heaps of dead leaves and old straw. The typical robust form, rich 

 in calcareous deposits, and often forming long plasmodiocarps is one of 

 the commonest species in the Swiss Alps in spring, where it occurs hi 

 company with Diderma niveum and Lepidoderma Carestianum on dead 

 twigs, leaves and grass close to the edge of melting snow. A variety of 

 P. vernum having small scattered sporangia, iridescent from absence of 

 lime, but with abundant white lime-knots, appears almost every autumn 

 in England and on the Continent ; if it were not for the darker brown 

 spores, this form would seem to be more nearly allied to P. cinereum. 



Hab. On dead leaves and twigs, straw, etc. — Bedfordshire (B.M. 

 1699) 

 1701) 



2281) 



Epping Forest (B.M. 1702) ; Christiania, 'part of type (B.M. 



Arolla, Switzerland (B.M. 2280) ; Jura Mountains (B.M. 



Austria (B.M. 2282) ; Portugal (B.M. 2283) ; Cuba (B.M. 429). 



43. P. gyrosum Rost. Mon., p. Ill (1875), in part. Plas- 

 modium creamy-white, or dull yellowish- white. Sporangia 

 sessile, much compressed, clustered, forming rosettes or 

 net-like plasmodiocarps one to many millimeters diam., 

 pinkish grey, usually seated on a pink or dull red hypothallus ; 

 sporangium-wall membranous with clustered deposits of white 

 or reddish lime-granules. Capillitiuni a scanty network of 

 hyaline threads with numerous large white transversely placed 

 fusiform or irregular lime-knots. Spores pale brownish- violet, 

 minutely spinulose, 7 to 10 //. diam. — Mass. Mon., 307, in 

 part ; Lister in Journ. Bot., xl. 210, t. 438, fig. 2; Petch in 

 Ann. R. Bot. Gard. Perad., iv. 339. Lignidium reni forme 

 Fr. Sym. Gast., 10 (1817) ? Fuligo septica Gmel., Lister 

 Mycetozoa, 66 (1894), in part. F. gyrosa Jahn in Ber. 

 Deutsch. Bot. Gesell., xx. 272 t. xiii, figs 3, 4 (1902). 



PI. 52. — a. rosette-like cluster of sporangia (Ceylon) ; b. capillitium and spores : 

 c. spore. 



In the first edition of the present work P. gyrosum was regarded 

 as a form of Fuligo septica ; gatherings from many parts of the world 

 have since fully established its position as a distinct species. It appears 



