TUBE-BEARING FUNGI. 191 



across in concentric layers corresponding to the summer wood. Also 

 as the wood becomes more decomposed, cracks and rifts appear along 

 these same lines. The mycelium then grows in abundance in these 

 rifts and forms broad and extensive sheets which resemble somewhat 

 chamois skin and is called **punk." Similar punk is sometimes 

 formed in conifers from the mycelium of Fomes pinicola. 



Polyporus sulphureus has long been known as an edible fungus, 

 but from its rather firm and fibrous texture it requires a different 

 preparation from the fleshy fungi to prepare it for the table, and this 

 may be one reason why it is not employed more frequently as an 

 article of food. It is common enough during the summer and espe- 

 cially during the autumn to provide this kind of food in considerable 

 quantities. 



Polyporus brumalis (Pers.) Fr. This pretty plant is found at all sea- 

 sons of the year, and from its frequency during the winter was named 

 brumalis, from bruma, which means winter. It grows on sticks and 

 branches, or on trunks. It usually occurs singly, sometimes two or 

 three close together. The plants are 3-6 cm. high, the cap 2-6 

 cm. in diameter, and the stem is 3-6 mm. in thickness. 



The cap is convex, then plane, and sometimes depressed at the 

 center or umbilicate. When young it is somewhat fleshy and pliant, 

 then it becomes tough, coriaceous, and hard when dry. During wet 

 weather it becomes pliant again. Being hard and firm, and tough, 

 it preserves long after mature, so that it may be found at any season 

 of the year. The cap is smoky in color, varying in shade, some- 

 times very dark, almost black, and other specimens being quite light 

 in color. The surface is hairy and the margin is often fimbriate with 

 coarse hairs. The stem is lighter, hairy or strigose. The tubes are 

 first white, then become yellowish. The tubes are very regular in 

 arrangement. 



Figure 186 represents well this species, three plants being grouped 

 rather closely on the same stick ; two show the under surface and 

 one gives a side view. The upper portion of the plate represents 

 two of the plants enlarged, the three lower ones being natural size. 

 The plant is very common and widely distributed over the world. 

 Those illustrated in the plate were collected at Ithaca. This species 

 is too tough for food. 



Many of the thin and pliant species of Polyporus are separated by 

 some into the genus Polystictus. The species are very numerous, as 

 well as some of the individuals of certain species. They grow on 

 wood or on the ground, some have a central stem, and others are 

 shelving, while some are spread out on the surface of the wood. One 



