INTRODUCTION 



A HOST-INDEX is ;i iieccssitv in the study of North American fungi at the present 

 (lay and everyone who has attempted to determine our species with an}- prospect of 

 success has been obliged to prepare such an. index for himself. The result is that 

 a number of persons, some of whom are not well provided with mycological works 

 except those which have been published within the last few years, are all spending 

 considerable time and labor in an effort to do the same thing. To make a complete 

 host-index is, for several reasons, quite out of the question but, believing that an 

 approximately complete list of our parasitic species and their hosts would aid mate- 

 rially in the advance toward a more accurate study of our mycological flora and 

 would tend to lessen the amount of indiscriminate species making which has already 

 become a serious evil, the present index, the result of work extending over several 

 years, has l)een prepared for publication. 



The basis of the present record is the "List of Works on North American Fungi" 

 by Farlow and Trelease, issued in 1887, and the "Supplement" issued the present 

 year. The species of fungi mentioned in the works wdiose titles are given in the 

 two papers just mentioned are here classified and arranged under their recorded 

 hosts. It has seemed best to give only those hosts which have already been record- 

 ed in print, for to go beyond that and record other hosts of the fungi of unpublished 

 collections might lead to confusion or might be considered an unwarranted anticipa- 

 tion of the proposed publications of other botanists. It should not be supposed, 

 however, that we have recorded the hosts mentioned in all the papers included in 

 the "List of Works on North American Fung-i." Some of the works there men- 

 tioned are so clearly inaccurate and unscientific that probably all respectable my- 

 cologists would agree that their contents had better be ignored. As it is, by far the 

 greater part of the works mentioned in the "List" are here included and it is proba- 

 ble that, if we have erred, it has beeii by including too many rather than too few of 

 them. 



In the nomenclature of the hosts themselves we have merely aimed at adopting 

 the names g-iven in standard works, such as Gray's Manual, the Synoptical Flora, 

 Watson's Index, the Flora of California, etc., which are in general use and accessi- 

 ble to anyone, avoiding any attempt to settle the recondite and disputed points which 

 concern the experts in Pluienogamic Botany. For mycological purposes it is of 

 slight consequence whether a phaenogamic species, as here given, had better be split 

 up into two closely related species or, on the other hand, united with another nearly 

 , related species. The fact remains that the same parasitic fungi are apt to occur on 

 t^ closely related Phaenogams and the present index will still serve as a general guide, 

 " — which is all that it purports to be in any case, even if the specific limitations ol the 

 hosts be hereafter changed by experts in that branch of botan}-. All we can expect 





