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..
The plants of this genus are tough and pliant, becoming hard when old, unless very watery, and when dry. The genus differs from the other tough and pliant ones by the peculiarity of the gills, the gills being notched or serrate on the edges. Sometimes this appearance is intensified by the cracking of the gills in age or in drying. The nearest ally of the genus is Panus, which is only separated from Lentinus by the edge of the gills being plane. This does not seem a very good character on which to separate the species of the two genera, since it is often difficult to tell whether the gills are naturally serrate or whether they have become so by certain tensions which exist on the lamellae during the expansion and drying of the pileus. Schrœter unites Panus with Lentinus (Cohn's Krypt. Flora, Schlesien, 3, 1; 554, 1889). The plants are usually very irregular and many of them shelving, only a few grow upright and have regular caps.
This is a large and handsome species, having a wide distribution in Europe and in this country, but it does not seem to be common. It grows on trunks, logs, stumps, etc., in the woods. It was quite abundant during late summer and in the autumn on fallen logs, in a woods near Ithaca. The caps are shelving, closely overlapping in shingled fashion (imbricated), and joined at the narrowed base. The surface is convex, and the margin is strongly incurved, so that each of the individual caps is shell-shaped (con-chate). The surface of the pileus is coarsely hairy or hispid, the surface becoming more rough with age. Many coarse hairs unite to form coarse tufts which are stouter and nearly erect toward the base of the cap, and give the surface a tuberculate appearance. Toward the margin of the cap these coarse hairs are arranged in nearly parallel lines, making rows or ridges, which are very rough. The hairs and tubercles are dark in color, being nearly black toward the base, especially in old plants, and sometimes pale or of a smoky hue, especially in young plants. The pileus is flesh color when young, becoming darker when old, and the flesh is quite thin, whitish toward the gills and darker toward the surface. The gills are broad, nearly white, flesh color near the base, coarsely serrate, becoming cracked in age and in drying, narrowed toward the base of the pileus, not forked, crowded, 4-6 mm. broad. The cap and gills are tough even when fresh. The plant has an intensely pungent taste.
Figures 131, 132 represent an upper, front, and under view of the pilei (No. 3315, C. U. herbarium).
Plate 42, Figure 131
Lentinus vulpinus. The coarse, hairy scales are black in old plants, paler, of a smoky hue, in younger ones (natural size). Copyright.
Lentinus lecomtei Fr., is a very common and widely distributed species growing on wood. When it grows on the upper side of logs the pileus is sometimes regular and funnel-shaped (cyathiform), but it is often irregular and produced on one side, especially if it grows on the side of the substratum. In most cases, however, there is a funnel-shaped depression above the attachment of the stem. The pileus is tough, reddish or reddish brown or leather color, hairy or sometimes strigose, the margin incurved. The stem is usually short, hairy, or in age it may become more or less smooth. The gills are narrow, crowded, the spores small, ovate to elliptical 5-6x2-3 µ. According to Bresadola this is the same as Panus rudis Fr. It resembles very closely also Panus cyathiformis (Schaeff.) Fr., and P. strigosus B. & C.
Lentinus lepideus Fr., [L.. squamosus (Schaeff.) Schroet.] is another common and widely distributed species. It is much larger than L. lecomtei, whitish with coarse brown scales on the cap. It is 12-20 cm. high, and the cap is often as broad. The stem is 2-8 cm. long and 1-2 cm. in thickness. It grows on wood.
Lentinus stipticus (Bull.) Schroet. (Panus stipticus Bull.) is a very small species compared with the three named above. It is, however, a very common and widely distributed one, growing on wood, and may be found the year around. The pileus is 1-3 cm. in diameter, whitish or grayish, very tough, expanded in wet weather, and curled up in dry weather. The stem is very short, and attached to one side of the cap. When freshly developed the plant is phosphorescent.
Lentinus vulpinus, front and under view (natural size). Copyright.