CHAPTER II 



THE PERENNIAL PSEUDORHIZA OF COLLYBIA FUSIPES 



Introduction — Historical Remarks — Fruit-body Clusters and their Pseudorhizae — 

 The Sujiposed Sclerotium — Evidence that the Pseudorhiza Persists — Mode of 

 Development of a Compound Pseudorhiza — Lateral Crafting — Healing of 

 Pseudorhizal Wounds — The Mycelium and the Problem of Parasitism — The 

 Functions of tiie Pseudorhiza and the Significance of its Persistency — Sarco- 

 safphd prntracla. 



Introduction. — Collybia fusipes, one of the best-know^l of the fleshy 

 fungi, commonly occurs on the ground near the trunks of trees, 

 particularly those of Beeches (Fagus) and Oaks (Quercus). The 

 fruit-bodies are sometimes solitary but they usually come up in 

 smaller or larger clusters, and two such clusters are shown in a 

 Beech grove at Kew Gardens in Fig. 188. The pileus, when fully 

 expanded, is about 1-5-2 -5 inches wide, but larger ones are not 

 rare and I have seen one six inches wide (the left fruit-body in 

 Fig. 189). The top of the pileus, when young, is reddish-bay ; but, 

 in age, it becomes dingy tan-colour and is often speckled with 

 numerous small dark spots and blotches as if it had been injured 

 in some way. The stipe varies from about 2 to 6 inches in length 

 and from about • 25 to 1 inch in thickness ; and it is usually more 

 or less fusiform (hence the specific name), being thickest in the 

 centre, tapering somewhat upwards toward the pileus, and tapering 

 greatly toward its base where it is attached in the soil. Its exterior 

 w^all is reddish-brown and cartilaginous, and within it is at first 

 fibrously stuffed, afterwards becoming somewhat hollow. The 

 spores are colourless, small, and thin- walled ; and each one passes 

 through all its developmental stages from its first origin to its dis- 

 charge from the sterigma in about one hour and five minutes.^ 



1 These Researches, Vol. II, 1924, pp. 44, 49, and 54. 



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