CHAPTER IX. 



THE TUBE-BEARING FUNGI. POLYPORACEAE. 



The plants belonging to this family are characterized especially 

 by a honeycombed truiting surface, that is, the under surface of the 

 plants possesses numerous tnbes or pores which stand close together 

 side by side, and except in a very few forms these tubes are joined 

 by their sides to each other. In Fisfii/iim the tubes are free from 

 each other though standing closely side by side. In Meruliiis dis- 

 tinct tubes are not present, but the surface is more or less irregu- 

 larly pitted, the pits being separated from each other by folds which 

 anastomose, forming a network. These pits correspond to shallow 

 tubes. 



The plants vary greatly in consistency, some are very fleshy and 

 soft and putrify readily. Others are soft when young and become 

 firmer as they age, and some are quite hard and woody. Many of 

 the latter are perennial and live for several or many years, adding a 

 new layer in growth each year. The larger number of the species 

 grow on wood, but some grow on the ground; especially in the genus 

 Boletus, which has many species, the majority grow on the ground. 

 Some of the plants have a cap and stem, in others the stem is ab- 

 sent and the cap attached to the tree or log, etc., forms a shelf, or 

 the plant ma\- be thin and spread over the surface of the wood in a 

 thin patch. 



In the genus Dd\ij/i\i the tubes become more or less elongated 

 horizontally and thus approach the form of the gills, while in some 

 species the tubes are more or less toothed or split and approach the 

 spine-bearing fungi at least in appearance of the fruit-bearing sur- 

 face. Only a few of the genera and species will be described. 



The following key is not complete, but may aid in separating some 

 of the larger plants : 



Tubes or pores free from each other, though stand- 

 ing closely side by side, l-htulitui. 



Tubes or pores not free, joined side by side . . . i. 

 I — Plants soft and fleshy, soon decaying, 2. 



Plants soft when young, becoming firm, some 

 woody or corky, stipitate, shelving, or spread 

 over the wood, Polyponts. 



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