The Saprophytic Fungi of Eastern Iowa. 



T. H. McBRIDE. 



THE POLYPOREi^. 



In Iowa as elsewhere in the world, the Polyporeai rank 

 next to the Agaricinea^ in numbers and general importance. 

 They resemble the Agarics, too, in habit; are lovers of the 

 forest and occur chiefly, though by no means exclusively, in 

 the wooded sections of our state. The species are both ter- 

 restrial and lignatile. In our experience the terrestrial forms 

 are entirely confined to our woodlands and groves, while, as 

 will appear later, lignatile forms are everywhere, wherever 

 wood under suitable conditions is suffering decay. Thus 

 typical forms mav be found on almost every stump, on pros- 

 trate logs and trees, on bridges, posts, and piers. The economic 

 importance of the family is accordingly for the most part 

 negative. A few of the terrestrial forms are edible although 

 Americans have never learned to eat them, and not a few 

 do service to the farmer by slowly pulling down the stumps 

 which otherwise might prove a serious obstacle. The very 

 habit, however, that makes such fungi serviceable, renders 

 them the omnipresent foe of architect and engineer. They 

 everywhere attack our beams and sills, cut off all posts 

 set in the earth and are very generally the agents which 

 bring to nothing railway ties and wooden structures resting 

 on the ground. Some knowledge of this particular group of 

 fungi would seem almost essential to the civil engineer. No 

 members of the group are purely parasitic; some, how^ever, 

 are partially so. These, as noted farther on, take advantage 



