The species which constitute this tribe are easily distinguished from all others by the sulphur-colored pulverulence which coats the pileus and stem like a universal veil. They appear thus far to be peculiar to this country. Though strongly resembling each other in the tribal character they are very diverse in other respects. One species, by its viscidity, connects with the preceding tribe; another by its differently colored tube mouths is related to the Luridi; and the third is peculiar in its ligneous habitat.
| Plant growing on the ground | 1 | |
| Plant growing on wood | B. hemichrysus | |
| 1. | Tubes adnate, of one color | B. Ravenelii |
| 1. | Tubes free, with red mouths | B. auriflammeus |
| Peck, Boleti of the U.S., p. 103. |
B. hemichry´sus B. and C.—half-golden. Pileus convex, at length plane or irregularly depressed, floccose-squamulose, covered with a yellow powder, sometimes cracked, bright golden-yellow. Flesh thick, yellow. Tubes adnate or decurrent, yellow, becoming reddish-brown, the mouths large, angular. Stem short, irregular, narrowed below, sprinkled with a yellow dust, yellowish tinged with red; mycelium yellow. Spores oblong, minute, dingy-ochraceous.
Var. muta´bilis. Flesh slightly changing to blue where wounded. Stem reddish, yellow within, sometimes eccentric. Spores oblong-elliptical, 7.5–9×3–4µ.
Pileus 1.5–2.5 in. broad. Stem about 1 in. long, 3–6 lines thick.
Roots of pine, Pinus palustris. The variety on stumps of Pinus strobus.
South Carolina, Ravenel; North Carolina, Curtis; New York, Peck.
The species is remarkable for its habitat, which is lignicolous. The New York variety grew on a stump of white pine. By its eccentric stem it connects this genus with Boletinus, through Boletinus porosus. According to the authors of this species it resembles Boletus variegatus. Peck, Boleti of the U.S.
B. Ravenel´ii B. and C.—after Ravenel. Pileus convex or nearly plane, slightly viscid when young or moist, covered with a sulphur-yellow powdery down, becoming naked and dull-red on the disk. Flesh whitish. Tubes at first plane, adnate, pale-yellow, becoming yellowish-brown or umber, dingy-greenish where bruised, the mouths large or medium size, subrotund. Stem nearly equal, clothed and colored like the young pileus, yellow within, with a slight evanescent webby or tomentose ring. Spores ochraceous-brown, 10–12×5–6µ.
Pileus 1–3 in. broad. Stem 1.5–4 in. long, 3–6 lines thick.