THE POLYPORACEAE OF WISCONSIN. 65 



Very common on all sorts of wood. 



My largest specimen is 10 cm. wide, 6 cm. long and 5 mm. thick; tlie 

 pores are 3 mm. in length. Some specimens are very much thicker, es- 

 pecially when young. One specimen measures 3 cm. in width, 1 cm. 

 in length and 2 cm. in thickness; the pores in this one are 0.4 mm. long. 

 This form seems to be more typical for young pilei, which are often 

 truly ungulate. 



Older or mature specimens may be dimidiate, helicoid, rosetted and 

 very much imbricated or they may be single and centrally attached on 

 the upper side of a limb. In color they vary from straw-yellow, 

 through tawny to gray, becoming black when weathered. They are 

 covered with a dense velvety pubescence and show few or many con- 

 centric furrows or sulcations. 



The margin becomes acute; it may be even, wavy or lobed and is 

 sometimes a little lighter than the pileus. The flesh is white and soft 

 but tough. The pores are small, round, obtuse when young, but be- 

 come more acute with age and sometimes even torn. In color they vary ; 

 some are white, some straw color, or tawny or slaty. In a few speci- 

 mens all of the pores are of a slaty gray, and in some there is a band 

 of slaty pores near the margin while the rest are yellow. However, it 

 appears that the mouth only has this color, the rest of the tube is white. 



The present species may be distinguished by its hirsuteness and the 

 more or less obtuse dissepiments. It is larger and thicker than P. 20- 

 natus and has smaller pores; it is more densely hirsute than P. velu- 

 iinus; and P. versicolor differs in its shining zones, thinner substance 

 and more acute dissepiments. 



Polystictus abietinus (Dicks) Fries (Plate IV, fig. 22.) 



Pileus thin, coriaceous, flaccid, effuso-reflexed, or sometimes entirely 

 resupinate, silky- villous, grayish white or with an ochraceous tinge, in- 

 distinctly zoned ; pores shallow, unequal ; dissepiments torn, violet, be- 

 coming pale ; spores elliptieal-oblong, 4 by 1.5 microns. 



Quite common throughout the pine belt of the north. Our speci- 

 mens have been collected from Crandon, Hazelhurst, Star Lake, Lady- 

 smith and Shanagolden, chiefly on hemlock, dead and living, also on 

 various pines, fir, and tamarack. It is usually smaller than P. per- 

 gamenus, which it resembles very much; however, it probably never 

 occurs on any other than coniferous trees. The surface is zoned with 

 concentric sulcations. The pores are larger, more delicate, and shal- 

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