TUBE-BEARING FUNGI. 173 



buff to dull reddish, to reddish-brown, tawny-brown, often yellowish 

 over a portion of the cap, usually paler on the margin. The flesh is 

 white or tinged with yellow, sometimes reddish under the cuticle. 

 The tubes are white when young and the mouths are closed (stuffed), 

 the lower surface of the tubes is convex from the margin of the cap to 

 the stem, and depressed around the stem, sometimes separating from 

 the stem. While the tubes are white when young, they become 

 greenish or greenish-yellow, or entirely yellow when mature. The 

 spores when caught on paper are greenish-yellow, or yellow. They 

 are oblong to fusiform, 12-15 // long. The stem is stout, even, or 

 much enlarged at the base so that it is clavate. The surface usually 

 shows prominent reticulations on mature plants near the tubes, 

 sometimes over the entire stem. This is well shown in Fig. 164 from 

 plants (No. 2886, C. U. herbarium) collected at Ithaca, N. Y. 



Figure 165 represents plants (No. 41 34, 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, some- 

 times 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. 1 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 bit- 

 ter. 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 sur- 

 face (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 12-18x4-5 /<. 



