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_. =Polystictus cinnamomeus= (Jacq.) Sacc., (_P. oblectans_ Berk. Hook. Jour. p. 51, 1845, Dec. N. A. F. No. 35: _P. splendens_ Pk., 26th Report N. Y. State Mus., p. 26) is a closely related species with the same habit, color, and often is found growing side by side with _P. perennis_. The margin of the cap is deeply and beautifully lacerate, as shown in the three other plants in Fig. 187. _Polystictus connatus_ Schw., grows in similar situations and one sometimes finds all three of these plants near each other on the ground by roadsides. _P. connatus_ has much larger pores than either of the other two, and it is a somewhat larger plant. Figure 187 is from a photograph of plants collected at Blowing Rock, N. C., during September, 1899. [Illustration: FIGURE 187.--Left-hand plant Polystictus perennis; right-hand three plants Polystictus cinnamomeus. All natural size. Copyright.] =Polystictus versicolor= (L.) Fr., is a very common plant growing on trunks and branches. It is more or less shelving, with a leaf-like pileus, marked by concentric bands of different colors. =P. hirsutus= Fr., is a somewhat thicker and more spongy plant, whitish or grayish in color, with the upper surface tomentose with coarse hairs. =P. cinnabarinus= (Jacq.) Fr., is shelving, spongy, pliant, rather thick, cinnabar colored. It grows on dead logs and branches. It is sometimes placed in the genus _Trametes_ under the same specific name. =Polystictus pergamenus= Fr., is another common one growing on wood of various trees. It is thin and very pliant when fresh, somewhat tomentose above when young, with faint bands, and the tubes are often violet or purple color, and they soon become deeply torn and lacerate so that they resemble the teeth of certain of the hedgehog fungi. [Illustration: PLATE 72, FIGURE 188.--Polyporus lucidus. Caps bright red or chestnut color, with a hard shiny crust (1/6 natural size). Copyright.]