This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
Polyporus brumalis (Pers.) Fr. - This pretty plant is found at all seasons 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.
Plate 71, Figure 186
Polyporus brumalis. Cap and stem brown, tubes white. Lower three plants natural size, upper one enlarged twice natural size. Copyright.
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, sometimes 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 very pretty species is the Polystictus perennis Fr. This grows on the ground and has a central stem. The plant is 2-3 cm. high, and the cap 1-4 cm. broad. The pileus is thin, pliant when fresh and somewhat brittle when dry. It is minutely velvety on the upper surface, reddish brown or cinnamon in color, expanded or umbilicate to nearly funnel-shaped. The surface is marked beautifully by radiations and fine concentric zones. The stem is also velvety. The tubes are minute, the walls thin and acute, and the mouths angular and at last more or less torn. The margin of the cap is finely fimbriate, but in old specimens these hairs are apt to become rubbed off. The left hand plant in Fig. 187 is Polyporus perennis.