[Illustration: PLATE 57, FIGURE 165.--Cap light brown, tubes greenish yellow or yellowish; stem in these specimens not reticulate (2/3 natural size). Copyright.] Figure 165 represents plants (No. 4134, C. U. herbarium) collected at Blowing Rock, N. C., in September, 1899. The plant is widely distributed and has long been prized as an esculent in Europe and America. When raw the plant has an agreeable nutty taste, sometimes sweet. The caps are sometimes sliced and dried for future use. It is usually recommended to discard the stems and remove the tubes since the latter are apt to form a slimy mass on cooking. =Boletus felleus= Bull. =Bitter.=--This is known as the bitter boletus, because of a bitter taste of the flesh. It usually grows on or near much decayed logs or stumps of hemlock spruce. It is said to be easily recognized by its bitter taste. I have found specimens of a plant which seems to have all the characters of this one growing at the base of hemlock spruce trees, except that the taste was not bitter. At Ithaca, however, the plant occurs and the taste is bitter. It is one of the large species of the genus, being from 8--12 cm. high, the cap 7--20 cm. broad, and the stem 1--2.5 cm. in thickness. The =pileus= is convex becoming nearly plane, firm, and in age soft, smooth, the color varying from pale yellow to various shades of brown to chestnut. The flesh is white, and where wounded often changes to a pink color, but not always. The =tubes= are adnate, long, the under surface convex and with a depression around the stem. The tubes are at first white, but become flesh color or tinged with flesh color, and the mouths are angular. The =stem= is stout, tapering upward, sometimes enlarged at the base, usually reticulated at the upper end, and sometimes with the reticulations over the entire surface (Fig. 166). The color is paler than that of the cap. The =spores= are oblong to spindle-shaped, flesh color in mass, and single ones measure 12--18 × 4--5 µ. The general appearance of the plant is somewhat like that of the _Boletus edulis_, and beginners should be cautioned not to confuse the two species. It is known by its bitter taste and the flesh-colored tubes, while the taste of the _B. edulis_ is sweet, and the tubes are greenish-yellow, or yellowish or light ochre. Plate 55 represents three specimens in color. =Boletus scaber= Fr. =Edible.=--This species is named the rough-stemmed boletus, in allusion to the rough appearance given to the stem from numerous dark brown or reddish dots or scales. This is a characteristic feature, and aids one greatly in determining the species, since the color of the cap varies much. The cap is sometimes whitish, orange red, brown, or smoky in color. The plant is 6--15 cm. high, the cap 3--7 cm. broad, and the stem 8--12 mm. in thickness.