Clarke : The Genus Tricholoma. 365 



All the species of Tricholoma, with three exceptions, are 

 terrestrial, growing on the ground ; the exceptions are : — 

 T. variegatum, on rotten wood ; T. immundimi, a rare species 

 grows on sheep-dung ; T. sordidum, about manure heaps. 

 The larger of the remaining species mostly grow in woodlands, 

 the smaller in pastures. 



Most of the species are autumnal, some late. A small 

 group, of which T. gamhosum is the type, are vernal, though 

 occasional specimens may be found during summer and early 

 autumn. T. gambosum comes in April, about St. George's day, 

 hence called St. George's ' mushroom ' — a good substantial 

 edible species ; others of this group, including ' Blewits,' have 

 also long been considered special delicacies, having a pleasant 

 odour like new flour. None are known to be truly poisonous, 

 though a few are rank and suspicious, and have such ob- 

 jectionable qualities that they are not likely to be tried as edibles. 

 Economically none are under any ban as being destructive, for 

 one reason perhaps, because none grow on living trees as is the 

 case with some Agarics. 



In point of number of species this is the largest of the 

 white-spored groups, and with the exception of Cortinarius, 

 is the most extensive genus in the whole range of the Order 

 Agaricaceae. Altogether about 200 species and a few varieties 

 have been described. 137 of these have been met with in 

 Europe, 113 in Great Britain, 68 in Yorkshire, and 41 in the 

 Mulgrave district. 12 of the latter were, when found, new 

 to Yorkshire. Tricholoma onychinum Fr. and T. jallax Peck, 

 were first British records. 



Fries divided the genus into seven classes in which the 

 character of the pileus is given primary consideration, as 

 follow : — 



1. Limacina. Pileus slimy or viscid. 



2. Genuina (type). Pileus fiocculose. 



3. Rigida. Pileus rigid. 



4. Sericella. Pileus silky. 



5. Guttata. Pileus spotted with drop like marks. 



6. Spongiosa. Pileus spongy. 



7. Hygrophana. Pileus watery. 



Sub-divisions of each of the above sections are made 

 according to minor characters.* 



* The names of the 137 European species were classified under 

 the above headings on seven large sheets hung on the schoolroom walls 

 where they could be seen at a glance and studied at leisure, along with a 

 large number of coloured drawings of the genus. A three column arrange- 

 ment is added that showed which of the 137 European species have been 

 met with in Britain, in Yorkshire and at Mulgrave. Short remarks were 

 made on the special features or connections of about 70 British species, 

 including the derivation of many of the technical names. 



1912 Dec. I. 



