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THE GENUS TRICHOLOMA. 



ALFRED CLARKE, 



H udders field. 



The genus Tricholoma was consitituted by Fries in his ' Systema 

 Mycologicum,' published in 182 1. As one of the white-spored 

 subgenera of Agaricus, it is distinguished from otlier white- 

 spored subgenera principally by the sinuate gills which are 

 neither decurrent as in Clitocybe, nor adnexed or adnate as in 

 Collybia, but have a more or less sudden curve or sinus at the 

 end of the gills nearest the stem, and in some species a short 

 tooth which runs slightly down the stem. 



This sinuate gill character is very distinct in most of the 

 species, though in some it is not quite so definite, consequently 

 reference must also be made to certain other characters of the 

 group for the determination of the species. 



The position assigned by Fries to this group corresponds 

 to Entoloma, with pink spores, Hebeloma, with brown spores, 

 and Hypholoma, with purple spores. 



There is nothing remarkable in the form of any of the 

 Tricholomas, the shape of all the species being fairly uniform 

 in general build, the only difference being in size. 



The prevailing colour is yellow, yellowish-brown, and 

 brown, a few species are lilac or purplish, there are no intensely 

 red or scarlet species as in the Russulas. They are mostly of 

 a robust build, having a fairly thick, fleshy pileus and a short 

 stout stem. None are what may be termed small. None have 

 any trace of a volva at the base of the stem ; nor is a ring ever 

 present, or a true veil, though sometimes there is a slight 

 veil-like floccose appendage adhering to the margin of the 

 pileus in the form of a fringe. It is from the latter character 

 the group received its name, trichos, a hair ; loma, a fringe. 



The pileus is never conical in outline nor truly umbilicate. 

 The stem, which is central and usually solid, is fibrously 

 fleshy throughout ; it is homogeneous and confluent with that of 

 the Hymenophorum, that is to say, the flesh which is composed 

 of a compacted bundle of fibres or strands of hyphae are 

 arranged lengthwise and continuous throughout the substance 

 of the stem and the pileus. In this it differs from, say Le- 

 piota, in which genus there is a distinct differentiation of 

 the strands at the apex of the stem where, in most species of 

 Lepiota, the stem fits into the pileus after the manner of a ball- 

 joint, and may be easily removed without apparent tearing of 

 the tissue. 



The surface of the stem is not hard, smooth and polished as 

 in Mycena, Collybia, etc., but more or less loosely fibrous. 



The gills are somewhat distinct from the pileus and in cer- 

 tain species separate from it as readily as in the genus Paxillus. 



Naturalist, 



