106 ENDOSPOREAE [DIDERMA 



Lister in Journ. Bot., xlvi. 217. Chondrioderma Lyallii Mass. 

 Mon., 201 (1892) ; Lister Mycetozoa, 81. Diderma Lyallii 

 Macbr. I.e., 99 (1899). 



Subsp. 2. — depianatum Lister : sporangia white or cream- 

 coloured, forming curved ring-shaped or net-like plasmodio- 

 carps; columella none, or represented by the thickened 

 orange base of the sporangium-wall ; spores 9 to 10 /x. — 

 Diderma depianatum Fr. Syst. My a, hi. 110 (1829) ; Berk, 

 in Sm. Engl. Fl., v. pt. 2, 312. D. contortum Hoffm. Fl. 

 Crypt. Germ., iii. tab. 9, fig. 2a (1795) ? Chondrioderma depian- 

 atum Rost. Mon., App. p. 17 (1876). C. mutabile Schroet. in 

 Cohn Krypt. Fl. Schles., iii. pt. 1, 123 (1885) ? 



PI. 89. — a. sporangia (Vosges) ; b. capillitium and spores with fragment of 

 sporangium-wall ; c. spore ; d. ring-shaped plasmodiocarp of subsp. depianatum 

 sporangium-wall partly broken away (England). 



PI. 90. — subsp. Lyallii. ; a. sporangia (Switzerland) ; b. capillitium and spores 

 with fragment of sporangium-wall ; c. spore. 



This species displays three well-marked phases. The type and the 

 subsp. Lyallii are essentially alpine forms, and occur in great abundance 

 on the turf of alpine pastures in springtime close to the edge of melting 

 snow ; connecting forms showing great variety in the shape of the 

 columella and size of the spores are frequently found (see R. E. Fries 

 in Arkiv. Bot., vi. no. 7, pp. 2, 8 ; Meylan in Bull. Soc. Vaud., xliv. 290). 

 The subsp. depianatum is the lowland phase of the species ; it is not 

 uncommon in this country. While some gatherings of this subspecies 

 have a definite columella and closely approach the type of D. niveum, 

 others show affinity with D. effusum in having more slender depressed 

 plasmodiocarps. The specimen in Berkeley's collection from Linlithgow 

 named by him Diderma cyanescens Fr., and by Rostafinski Chondrio- 

 derma niveum (K. 1435), is the subsp. depianatum, having the lower 

 part of the inner wall and base orange, and the columella depressed ; 

 it has the same rigid warted threads as the typical form. D. con- 

 tortum Hoffm. is cited by Fries as a synonym for his D. depianatum, 

 but it is somewhat doubtful from the figure and description if they refer 

 to the present species or to a nearly sessile form of D. hemisphericum. 

 The type of Chondrioderma physaroides Rost. gathered by A. de 

 Candolle " on mountain land, close to perpetual snow," is now in the 

 Geneva Museum ; it is the typical form of the present species ; so also 

 is Diderma albescens Phill., gathered by Harkness on the Blue Canon, 

 California. 



Hab. On turf, twigs, etc., in alpine regions ; subsp. depianatum on 

 leaves and twigs on lower ground. — Near Berlin (B.M. 2401) ; Switzer- 

 land (B.M. 2402) ; Norway (B.M. slide) ; South Tyrol (B.M. 2404) ; 

 California (B.M- 1306) : subsp. Lyallii— Sweden (B.M. 2403) ; Saas, 

 Switzerland (B.M. 1307); Jura (B.M. 2405); Oregon Boundary, 

 U.S.A. (K. 380) : subsp. depianatum — Chislehurst, Kent (B.M. 27) ; 

 Carlisle (B.M. 1305) ; Appin, Scotland (K. 410) ; Linlithgow (K. 1435) ; 

 North Wales (B.M. 2406) ; Portugal (B.M. 2407). 



7. D. testaceum Pers. Syn., 167 (1801). Plasmodium 

 yellowish-buff {fide Torrend). Sporangia sessile, subglobose, 

 depressed on a broad base, sometimes confluent, 0-8 mm. 



