110 THE POLYPORACEAE OF WISCONSIN. 



Polyporus arcularius (Batsch) Fries. 



Pileus coriaceous, tough, convex, subumbilicate, zonate, brown scaly 

 at first, then glabrous, yellowish, the margin strigose; the stipe shoit, 

 slightly squamulose, brownish; pores oblong, thin, entire, whitish, 

 fairly large ; spores 3 by 8 microns. 



Macbride (15, p. 30) says of them "Lignatile, not rare in early sum- 

 mer in wooded regions, easy to recognize by the depressed pileus, thin 

 context and large rhomboidal pores at first whitish then on drying yel- 

 lowish. ' ' 



Quite common on sticks and logs in the woods. Localities : Madison, 

 Horicon, Oakfield, Bangor, Crandon and Ladysmith. The largest had 

 a diameter of 3 cm. ; the stipe 4 cm. in length and 4 mm. in diameter. 

 The length of the stipe varies from 1 to 5 cm. 



The species is very closely related to P. hrumalis from which it is 

 not always easy to separate it. It is usually lighter in color, thinner 

 and more depressed in the center than P. hrumalis. Its most distinc- 

 tive features are the large rhomboidal pores and its prevailing occur- 

 ence in spring and early summer. P. lentus Berk., is very much like P. 

 arcularius, but its pores are white, roundish or subquadrate and much 

 more decurrent, running soemtimes down to the base. 



The stem may be excentric but is usually central. 



The specimen in North American Fungi agrees weU with ours but 

 the C. A. F. specimen no. 58 is a little darker. 



Polyporus hrumalis Fries (Plate XIII, fig. 47). 



Pileus 3 to 12 cm. across, thin, pliant, then coriaceous and rigid, 

 more or less umbilicate, during the first year umber and densely vil- 

 lous, in the second year minutely scaly, becoming smooth, and paler; 

 pores shallow, large, angular, and usually elongated radially, white, 

 then yellowish, dissepiments thin, very minutely toothed at the margin ; 

 stem colored like the pileus, velvety or squamulose, spores colorless, lin- 

 ear oblong, sometimes slightly curved, 5 to 6 by 2 microns. 



Winter characterizes the species as follows: "A very variable species, 

 and hence having many synonyms which are in part doubtful. It ap- 

 pears that the well marked form characterized by small roundish ob- 

 tase pores — Polyporus tomentosus Rostk., in Sturm, Deutschl. Flora 

 3, p. 25, Taf . 13, and Polyporus trachypus Rostk., (1. c. p. 27, Taf. 14) 

 belong to P. hrumalis, while P. intermedius Rostk., (1. c. IV. Bd., p. 69, 

 Taf. 33) and P. alveolarius Rostk., (1. c. 27/28 Heft, p. 29, Taf. 15) had 

 better be referred to P. arcularius Batsch." (28, p. 450.) 



