This section is from the book "Our Edible Toadstools and Mushrooms and How to Distinguish Them", by W. Hamilton Gibson. Also available from Amazon: Our Edible Toadstools And Mushrooms And How To Distinguish Them.
Pileus: Rounded convex; diameter two to five inches; surface occasionally smooth and viscid when moist; color usually brownish red, but varying from orange brick red or even black in certain varieties to yellow or whitish.
Tube surface: Rounded, cushion-like; whitish at first, becoming dingy; tube openings small and round, and rather long as seen in section.
Spores: Reddish brown.
Stem: Solid, dingy white, tapering slightly above, more or less thickly beset with brownish, fibrous, dot-like scales, this being the most pronounced botanical character for identification.
Flesh: White or dingy in certain varieties, often changing to blue, brown, pinkish, or black where wounded.
Taste: Negatively pleasant.
Habitat: A common and widely distributed species, with many variations of color. Found in woods and shaded waste-places.
Plate XXI Boletus Scaber.
This is a very common mushroom in our woods all through the summer and autumn, in reasonably moist weather. It is figured in Plate 21. The cap of an average specimen expands four inches or more, is of a brown or brownish buff color, and viscid when moist. The pore-surface is dingy white, the tube orifices being quite minute and round - not so conspicuously angular or honey-combed as in other species - and with occasional reddish stains, presumably a deposit from the floating spores, which are tawny reddish. The flesh is dirty white, the stem solid, contracting upwards, and rough with fibrous brownish scaly points - whence the name "scaber" - often arranged somewhat in vertical lines. Epicures fail to agree as to the esculent qualities of this mushroom. It is certainly inferior to the edulis.