At Ithaca, N. Y., the plant is sometimes abundant in late autumn in grassy places near or in groves. The Figure [159] is from plants (No. 2508 C. U. herbarium) growing in such a place in the suburbs of Ithaca. At Blowing Rock, N. C., the plant is often very abundant along the roadsides on the ground during August and September.
Paxillus rhodoxanthus (Schw.)—This species was first described by de Schweinitz as Agaricus rhodoxanthus, p. 83 No. 640, Synopsis fungorum Carolinæ superioris, in Schriften der Naturforschenden Gesellschaft 1: 19–131, 1822. It was described under his third section of Agaricus under the sub-genus Gymnopus, in which are mainly species now distributed in Clitocybe and Hygrophorus. He remarks on the elegant appearance of the plant and the fact that it so nearly resembles Boletus subtomentosus as to deceive one. The resemblance to Boletus subtomentosus as one looks upon the pileus when the plant is growing on the ground is certainly striking, because of the reddish yellow, ochraceous rufus or chestnut brown color of the cap together with the minute tomentum covering the surface. The suggestion is aided also by the color of the gills, which one is apt to get a glimpse of from above without being aware that the fruiting surface has gills instead of tubes. But as soon as the plant is picked and we look at the under surface, all suggestion of a Boletus vanishes, unless one looks carefully at the venation of the surface of the gills and the spaces between them. The plant grows on the ground in woods. At Blowing Rock, N. C., where it is not uncommon, I have always found it along the mountain roads on the banks. It is 5–10 cm. high, the cap from 3–8 cm. broad, and the stem 6–10 mm. in thickness.
The pileus is convex, then expanded, plane or convex, and when mature more or less top-shaped because it is so thick at the middle. In age the surface of the cap often becomes cracked into small areas, showing the yellow flesh in the cracks. The flesh is yellowish and the surface is dry. The gills are not very distant, they are stout, chrome yellow to lemon yellow, and strongly decurrent. A few of them are forked toward the base, and the surface and the space between them are marked by anastomosing veins forming a reticulum suggestive of the hymenium of the Polyporaceæ. This character is not evident without the use of a hand lens. The surface of the gills as well as the edges is provided with clavate cystidia which are filled with a yellow pigment, giving to the gills the bright yellow color so characteristic. These cystidia extend above the basidia, and the ends are rounded so that sometimes they appear capitate. The yellow color is not confined to the cystidia, for the sub-hymenium is also colored in a similar way. The spores are yellowish, oblong to elliptical or spindle-shaped, and measure 8–12 × 3–5 µ. The stem is the same color as the pileus, but paler, and more yellow at the base. It is marked with numerous minute dots of a darker color than the ground color, formed of numerous small erect tufts of mycelium.
Figure [160] is from plants (No. 3977 C. U. herbarium) collected at Blowing Rock, N. C., during September, 1899. As stated above, the plant was first described by de Schweinitz as Agaricus rhodoxanthus in 1822. In 1834 (Synop. fung. Am. Bor. p. 151, 1834) he listed it under the genus Gomphus Fries (Syst. Mycolog. 319, 1821). Since Fries changed Gomphus to Gomphidius (Epicrisis, 319, 1836–1838) the species has usually been written Gomphidius rhodoxanthus Schweinitz. The species lacks one very important characteristic of the genus Gomphidius, namely, the slimy veil which envelops the entire plant. Its relationship seems rather to be with the genus Paxillus, though the gills do not readily separate from the pileus, one of the characters ascribed to this genus, and possessed by certain species of Gomphidius in even a better degree. (In Paxillus involutus the gills do not separate so readily as they do in certain species of Gomphidius.) Berkeley (Decades N. A. Fungi, 116) has described a plant from Ohio under the name Paxillus flavidus. It has been suggested by some (see Peck, 29th Report, p. 36; Lloyd, Mycolog. Notes, where he writes it as Flammula rhodoxanthus!) that Paxillus flavidus Berk., is identical with Agaricus rhodoxanthus Schw.
Paxillus rhodoxanthus seems also to be very near if not identical with Clitocybe pelletieri Lev. (Gillet, Hymenomycetes 1: 170), and Schroeter (Cohn's Krypt, Flora Schlesien, 3, 1: 516, 1889) transfers this species to Paxillus as Paxillus pelletieri. He is followed by Hennings, who under the same section of the genus, lists P. flavidus Berk., from N. A. The figure of Clitocybe pelletieri in Gillet Hymenomycetes, etc., resembles our plant very closely, and Saccardo (Syll. Fung. 5: 192) says that it has the aspect of Boletus subtomentosus, a remark similar to the one made by de Schweinitz in the original description of Agaricus rhodoxanthus. Flammula paradoxa Kalch. (Fung. Hung. Tab. XVII, Fig. 1) seems to be the same plant, as well as F. tammii Fr., with which Patouillard (Tab. Anal. N. 354) places F. paradoxa and Clitocybe pelletieri.
Paxillus atro=tomentosus (Batsch) Fr.—This plant is not very common. It is often of quite large size, 6–15 cm. high, and the cap 5–10 cm. broad, the stem very short or sometimes long, from 1–2.5 cm. in thickness. The plant is quite easily recognized by the stout and black hairy stem, and the dark brown or blackish, irregular and sometimes lateral cap, with the margin incurved. It grows on wood, logs, stumps, etc., during late summer and autumn.
Figure 161.—Paxillus atro-tomentosus, form hirsutus. Cap and stem brownish or blackish (natural size, small specimens, they are often larger). Copyright.
The pileus is convex, expanded, sometimes somewhat depressed, lateral, irregular, or sometimes with the stem nearly in the center, brownish or blackish, dry, sometimes with a brownish or blackish tomentum on the surface. The margin is inrolled and later incurved. The flesh is white, and the plant is tough. The gills are adnate, often decurrent on the stem, and easily separable from the pileus, forked at the base and sometimes reticulate, forming pores. Spores yellowish, oval, 4–6 × 3–4 µ. Stevenson says that the gills do not form pores like those of P. involutus, but Fig. [161] (No. 3362 C. U. herbarium) from plants collected at Ithaca, shows them well. There is, as it seems, some variation in this respect. The stem is solid, tough and elastic, curved or straight, covered with a dense black tomentum, sometimes with violet shades. On drying the plant becomes quite hard, and the gills blackish olive.