CHAPTER I 



THE PSEUDORHIZA 



Introductory Remarks — Collybia radicata — Mycena galericulata — Coprinus 



mdcrorhizus. 



Introductory Remarks. — The stipes of the fruit-bodies of certain 

 Agaricaceae are prolonged downwards through the soil for several 

 inches by so-called rooting bases. For rooting base Fayod ^ has 

 substituted the excellent term pseudorhiza. Among the species 

 having fruit-bodies with a characteristic pseudorhiza may be 

 mentioned : Collybia radicata, C. longipes, C. pulla, Tricholoma 

 macrorhizum, Pleurotus Ruthae, P. citrinatus, Pholiota radicosa, 

 Flammula inopus, Coprinus macrorhizus, and Collybia fusipes. In 

 all these species, with the exception of Collybia fusipes, the pseudo- 

 rhiza is annual and unbranched. In Collybia fusipes, as we shall 

 see, the pseudorhiza is perennial and branched. 



A pseudorhiza forms a link between a mycelium vegetating in 

 a buried root or other buried nutrient substratum and the aerial part 

 of the fruit-body which produces and liberates spores. In forming 

 such a link, it is analogous to certain pseudo-sclerotia, sclerotia, 

 and mycelial cords, but it differs from these structures in being a 

 specialised part of a stipe of a fruit-body and not part of a mycelium. 



The observations on the pseudorhizae of Collybia radicata and 

 Coprinus macrorhizus about to be recorded were made for the most 

 part in England during the years 1910-1915, and a brief account of 

 them was presented at the Ontario meeting of the American Phyto- 

 pathological Society in 1919.^ 



1 V. Fayod, " Prodrome d'une Histoire Naturelle des Agaricines," Ann. Sci. 

 Nat., T. IX, 1889, p. 214. 



2 A. H. R. Buller, "The Pseudorhiza of certain Saprophytic and Parasitic 

 Agaricineae," Phytapalhology, Vol. X, 1920, p. 316. 



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