PLANTS OF IOWA 69 



POLYSTICTUS. 



854. P. arcticus, Fries. 



On dead standing trunk of oak, not common. 



855. P. hirsutus, Fries. 



On wood of all sorts, perhaps our most common Poly- 

 pore. 



856. P. zonatus, Fries. 

 Not common. 



857. P. versicolor, (Linmeus) Fries. 



Very common on stumps and half -buried roots. 



858. P. cinnabarinus, (Jacquin) Fries. 

 Very common on soft woods. 



859. P. pergamenus, Fries. 

 Common on trunks of all sorts. 



860. P. biformis, Klotz. 



861. P. conchifer, Schweinitz. 



Very common on dead branches of white elm, but per- 

 ishing after the twig falls to the ground. 

 Fomes. 



862. F. reniformis, Morgan. 

 Resembles applanatus. 



863. F. rimosus, Berkeley. 



Not common. Found mostly on oak. 



864. F. igniarhis, (Linnaeus) Fries. 



Very common on various trees, especially on oak. 



865. F. formentarius, (Linnaeus) Fries. 

 Found on birch in this state. 



866. F. applanatus, (Persoon) Wallroth. 

 Everywhere common on trees of all sorts. 



867. F. ulmariuSj Fries. 



Seems to be confined to White Elm. 



868. F. conglobatus, Berkeley. 



Not common. On the sides of standing trees. 



869. F. lucidus, (Leys.) Fries. 



Common. On ground about the base of stumps, espe- 

 cially in low, marshy ground. 



