PILEATE HYDNACEAE FROM IOWA 415 



NOTES ON SOME PILEATE HYDNACEAE FROM IOWA. 



GUY WEST WILSON. 



The Hydnaceae, or spine fungi, is one of the smaller families of 

 the Agarieales, or. as they were known to the older mycologists, 

 the Hynienomyeetes. numbering as it does only about five hun- 

 dred species. Of these some are widely dispersed and rather 

 common while others are quite sporadic or even local in their 

 occurrence. Only a few members of the family are common in 

 our state, yet their number is more considerable than the pub- 

 lished accounts would indicate, as but four species appear to nave 

 been recorded from Iowa. Greene in his Plants of Iowa does not 

 even mention the family, while two other papers, one by Hess 

 and Yandivert 1 and one by Shimek 2 include a single species each. 

 The most considerable list of Iowa species is given by Banker' 

 who includes references to three. The present paper includes 

 fifteen species, all but one of which are represented in the her- 

 barium of the State University. 



The taxonomic treatment of the Hydnaceas, in common with 

 that of related families, has been subject to various vicissitudes 

 both as to extent of the group and as to the arrangement of the 

 species. Under the old concept two types of pileate forms were 

 included. Those forms having the teeth at least approximately 

 terete were all referred to the genus Eydnum, while those with 

 decidedly flattened teeth were designated as the genus Irpex. 

 The present paper is concerned only with the pileate species of 

 the first group. Numerous attempts have been made to segregate 

 the old genus Hydnum. As might be expected these have met 

 with varying degrees of success or failure according to the grasp 

 which their author had upon the relative importance and tax- 

 onomic value of the characters which were employed. Perhaps 

 the most rational attempt at a revision of the group is that of 

 Banker 3 who in his careful treatment of the American sp< 



iHess and Yandivert, Bacidiomycetes of central Iowa : Proc. Iowa Acad. 

 Scl., VII, 1900, 183-186, pi. 16. 



2 Shimek, The Plant geography of the Lake Okoboji region: Bull. Labs. Nat. 

 Hist. Univ. Iowa. 7 2 . 1915, 1-90, pi. 1-S and map. 



3 Banker. A contribution to the revision of the Xorth American Hydnaceae. 

 Mem. Torrev Club, 12, 1906, 99-194. 



