Woods and copses. South Carolina, Ravenel; North Carolina, Curtis; New York, Peck; New England, Frost.
This is a very distinct and very beautiful species. Mr. Ravenel remarks in his notes that “this plant is not infested by larvæ and preserves more constant characters than any other Boletus with which I am acquainted.” The webby powdered filaments constitute a universal veil which at first covers the whole plant and conceals the young tubes. As the pileus expands this generally disappears from the disk, and, separating between the margin and the stem, a part adheres to each. The flesh is sometimes stained with yellow. The tubes in some instances become convex and slightly depressed around the stem. They are almost white when young, and often exhibit brownish hues where wounded. The plant is sometimes cespitose. I have observed a greenish tint to the freshly shed spores, but it soon disappears. Boletus subchromeus Frost Ms. is this species. Peck, Boleti of the U.S.
B. auriflam´meus B. and C.—flaming yellow. Pileus convex, dry, powdered, bright golden-yellow. Flesh white, unchangeable. Tubes plane or convex, free, yellow, their broad angular mouths scarlet. Stem slightly tapering upward, powdered, colored like the pileus. Spores 10–12.5×5µ.
Pileus 8–12 lines broad. Stem 1–1.5 in. long.
Woods. North Carolina, Curtis; New York, Peck.
This is evidently a rare species and as beautiful as it is rare. The whole plant is bright-yellow except the tube mouths, and is sprinkled with yellow dust or minute yellow branny particles. In the New York specimen the scarlet color is wanting in the marginal tube mouths and the stem is marked with fine subreticulating elevated lines. In other respects it agrees well with the diagnosis of the species. Peck, Boleti of the U.S.
Subpruinosi—sub, pruina, hoar frost.
Pileus glabrous, but more often pruinose. Tubes adnate, yellowish. Stem equal, even, neither bulbous nor reticulated.
The species of this tribe have the pileus neither viscid nor distinctly and permanently tomentose. Typically it is glabrous or merely pruinose, but Fries has admitted into the group one species with a pulverulent, and one with a silky pileus. The species are not sharply distinguished from those of the following tribes, and possibly some have been admitted here which might as well have been placed there. Some of the species are variable in color and their characters are not sufficiently well known.
| Tubes bright-yellow, golden or subochraceous | 1 | |
| 1. | Tubes pale or whitish-yellow | 6 |
| 1. | Tubes changing to blue where wounded | 2 |
| 1. | Tubes not changing to blue | 3 |
| 2. Stem pallid, with a circumscribing red line at the top | B. glabellus | |
| 2. Stem yellow, sometimes with red stains | B. miniato-olivaceus | |
| 2. Stem red, yellow at the top | B. bicolor | |
| 3. | Stem viscid or glutinous when moist | B. auriporus |
| 3. | Stem not viscid | 4 |
| 4. Plant growing on Scleroderma | B. parasiticus | |
| 4. Plant terrestrial | 5 | |
| 5. | Tubes greenish-yellow | B. alutaceus |
| 5. | Tubes golden-yellow | B. tenuiculus |
| 6. Pileus reticulated with subcutaneous brown lines | B. dictyocephalus | |
| 6. Pileus not reticulated | 7 | |
| 7. | Tubes changing to blue where wounded | B. pallidus |
| 7. | Tubes not changing to blue | 8 |
| 8. Stem uniformly colored | B. subglabripes | |
| 8. Stem yellowish, streaked with brown | B. innixus | |
| Peck, Boleti of the U.S. |