GENERAL INTRODUCTION 15 



and other points. A few species have been received from isolated 

 points hut usually such arc common and of wide distribution. The 

 main central portion of the Southern Peninsula nortb of latitude 

 }:! has inti been touched; and from the iron-bearing regions of the 

 Dorthern Peninsula there are no records. Isle Royale was visited 

 in a dn season and there were lew important finds. Houghton. 

 Marquette, Munising and Saul1 Bte. Marie were the centers of one 

 season's extensive collecting and we have a Pair idea of their summer 

 flora; concerning the many autumn species which assuredly grow in 

 the coniferous regions of the uorthern hair of the state, we have 

 little Information, as most students ami collectors musl return t<> 

 their school duties before October. 



The principal species of held and lawn seem to he equally dis- 

 tributed throughout the state: here may he mentioned Psalliota 

 campestris and Psalliota arvensis, Ma/r(i8rnius oreades, Psilocybe 

 esicii, Lepiota nwicina and the Coprini. It appears thai L<\- 

 piota Morgani begins to disappear in the latitude of Lansing; that 

 Amanita caesarea scarcely enters our southern border. The species 

 which grow only on distinctly sandy soil are apparently distributed 



o • t . ii, 



throughout the sandy regions of the state although in many cases 

 the records are not complete; lor example, Amanita russuloides 

 ami Amanita spreta have been found only at New Richmond whereas 

 Ru88ula delica is abundant in sand under copses ami groves all 

 along the <l real Lakes, hut less a lunula nt in the interior of the state. 

 Many species doubtless prefer a clay soil ami are distributed accord- 

 ingly. By far the larger number of species are. however, dependent 



for their distribution on the character of the forest. This is most 



sharply illustrated by the difference between the flora of the coni- 

 ferous regions north of latitude 44 and along the eastern and 

 western border of the state where conifers have existed in the past, 

 and of the hardwood forests and woodlots of the southern portion. 

 The genus Cortinarius is composed of seven large subgenera. Of 

 these, the subgenera Bulbopodium ami Phlegmacium have ;i large 

 number of representatives in the hardwood region, hut are poorly 

 represented in the north; on the other hand, the subgenera Tela 

 nioiiia and Ilydrocyhe occur in large quantities in the coniferous 

 regions. Whatever factors, therefore. Influence distribution of con- 

 ifers doubtless affect also the distribution of certain Agarics. It 

 is much to be regretted thai we have so little data concerning the 

 original mushroom flora of the 15,000 square miles of the central 

 portion of the Southern Peninsula once covered by white pine 



forests. The nearest approach to original conditions, recorded in 



