This section is from the book "Mushrooms Of America, Edible And Poisonous", by Julius A. Palmer. Also available from Amazon: Mushrooms of America, Edible and Poisonous.
1. Boletus felleus. Bitter Boletus.
2. Boletus alveolatus, Crimson Boletus.
3, 4. Boletus luridus, Lurid Boletus.

Figure 1 above is very much like Figures 2 and 3, Plate VII., of Edible Mushrooms, from which it is easily distinguished by its bitter taste and rosy tubes. Figure 2 is a distinctively American species, and the authority for suspecting it is found in the fact that all Boleti which have red or red-mouthed tubes have been considered poisonous. Although valuable for an illustration of the lurid Boleti, this variety is probably edible. FIGURE 3 is easily confounded with Figures 4 and 5, Plate VII., of Edible Mushrooms, if attention is not paid to the color of the tubes.
 
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