-'j-i THE JOlTJtXATi OF HOTANT 



ARCYRIA VIRESCENS, sp. w. 



Bv G. Listeb, F.L.S. 



Among the specimens of Malayan Mycetozoa obtained by 

 Mr. I. H. Burkill, F.L.S., Director of the Botanic Gardens, Singa- 

 pore, is a handsome species of Arcyria with yellowish-green spores. 



II had developed on a block of wood in orchid pits in the Gardens in 

 February 1916, and was courteously sent to me for identification. 

 The striking features are the green spores, the long slender stalks, 

 and the loose columns of buff or khaki-coloured capillitium, the 

 threads of which are marked with scattered groups of prominent 

 transverse ridges. I wrote to Mr. Burkill suggesting that he had 

 met with a new species, and expressing the hope that more of it- 

 might be found. 



The integrity of the species has been well established by the 

 observations of Mr. A. R. Sanderson, F.L.S., who collected it at 

 Naboda, Ceylon, in August 1918, and during his residence in the 

 southern part of the Malay Peninsula from 1919 to 1921 he found it 

 was not uncommon in the neighbourhood of Johore. 



There is also a gathering of the same species in the Kew Herbarium 

 from North Queensland (No. 155) collected by Pentzke near the 

 Daintree River over forty years ago. (I am indebted to Miss E. M, 

 Wakefield for deciphering "Daintree River," and for explaining the 

 collector's name, whieh is written " Pentzoke " on the mounting sheet 

 by mistake.) It is in poor condition and consists of a tangle of 

 apparently weathered olive-brown capillitium, without stalks and with 

 few spores; the rather stout threads show the characteristic groups 

 of prominent transverse ridges which, apart from the other features. 

 distinguish the new species from Arcyria nutans Grev. and 

 A. Oerste&tii Host. The specimen is marked " Hemiarcyria fuli- 

 t/iiirit" but is clearly different from the type specimen of II. j'uli- 

 ginea Cooke and Massee from New South Wales, laid out on the 

 same sheet, which is a faded form of Arcyria Oerstedtii. 



The following is a detailed description of the new green-spored 

 species, for which I propose the name Arcyria virescens. 



Arcyrea virescens, sp. n. Plasmodium V Sporangia stalked, 

 cylindrical. Stalks slender, straight or flexuose, dark olive-green, 

 0*5 to 1*5 mm. long, arising from a membranous hypothallus, loosely 

 grouped or united in clusters of three to ten, and widening upwards 

 into narrow funnel-shaped sporangial cups; 'walls of the cup mem- 

 branous, reticulated and spinose on the inner side. Capillitium a. 

 loose elastic network of dull ochraceous or khaki-coloured threads, 

 unattached to the cup and expanding into a column about 6mm. 

 long; capillitium threads 4 to 0/x diam.. marked with scattered 

 groups of close-set prominent transverse ridges, 3 to 5/x deep, arranged 

 more or less in a loose spiral; the remaining surface irregularly 

 reticulated and roughened with delicate often broad-based spines. 

 Spores yellowish-green in mass, 7 to 8^t diam., smooth except for a 

 few scattered warts. 



Habitat on dead wood ; Ceylon, Malay Peninsula, Queensland. 



