COMPARATIVE STUDIES IN THE POLYPORACEAE 



L. 0. OVERHOLTS 



Formerly Rufus J. Lackland Fellow in the Henry Shaw School of Botany 



of Washington University 



The subclass Basidiomycetes of the class Fungi contains a 

 natural group of plants sharply separated from related 

 groups in that the hymenium (basidia, paraphyses, etc.) forms 

 the lining of hollow tubes on the ventral surface of the fruit 

 body. This group of plants constitutes the tribe Polyporeae. 

 It is divided into two families, the Boletaceae and the Polyp- 

 oraceae. The Boletaceae are separated from the Polyp- 

 oraceae in that they are fleshy and soon decay and the tubes 

 are easily separated from the pileus, while the Polyporaceae 

 vary in texture from coriaceous to hard and woody, and the 

 tubes are inseparable from the pileus. These characters are 

 susceptible of some variation, as there are a very few fleshy 

 species in the latter family, and in two or three cases the 

 hymenium is waxy and the tubes separable. In this article 

 we are concerned only with the Polyporaceae. 



Historical 



Accurate knowledge of the classification of the Polyporeae 

 dates back only to the last few years of the eighteenth or the 

 beginning of the nineteenth century. The first attempt worthy 

 of consideration was that of Persoon in 1801, although we still 

 have occasion to refer to articles by earlier writers, especially 

 Bulliard (Herbier de la France, 1780-1793), Schaeffer (Fung. 

 Bav. 1780), and Sowerby (Eng. Fung. 1797-1809). These 

 three, while contributing considerable in the way of illustra- 

 tions of the species known at that time, knew very little about 

 the correct classification of the species they illustrated. The 

 binomial method of naming species had come into general 

 use following its introduction by Linnaeus (Species Plan- 

 tarum) in 1753, and many new species were described in the 

 succeeding years, but the descriptions were inadequate and 



Ann. Mo. Bot. Gard., Vol. 2, 1915 



(667) 



