This Boletus belongs to the tribe Viscipelles. It is remarkable for and easily recognized by the inflexed margin of the pileus, which imitates to some extent the appendiculate veil of Boletus versipellis. It sometimes grows in tufts. The paper in which fresh specimens were wrapped was stained yellow. Boletus Braunii Bres. has an inflexed margin, but that is a much larger plant with a yellowish-brown pileus, a fibrillose stem and much smaller spores. Peck, Bull. Torr. Bot. Club, Vol. 22, No. 5.
B. fla´vus With. Pileus convex, compact, covered with a brownish separating gluten, pale-yellow. Flesh pale-yellow. Tubes large, angular, adnate, yellow. Stem yellow, becoming brownish, reticulated above the membranous fugacious dirty yellowish annulus. Spores 8–10×3–4µ.
Pileus 2–5 in. broad. Stem 2–3 in. long, 6–10 lines thick.
Woods. Minnesota, Johnson; Wisconsin, Bundy.
This is apparently a rare species in this country. I have not seen it. It is said to resemble B. luteus, from which it is separated by the large angular mouths of the tubes. In British Fungi the spores are described as “spindle-shaped, yellowish-brown;” in Sylloge, as “ovoid-oblong, acute at the base, granulose, pale ochraceous.” Peck, Boleti of the U.S.
B. fistulo´sus Pk. Pileus convex, viscid, glabrous, yellow, the margin at first incurved or involute. Flesh yellow. Tubes plane or subventricose, medium size, round with thin walls, adnate or sometimes depressed around the stem, yellow. Stem rather slender, subequal, viscid, glabrous, hollow, yellow, with a white mycelioid tomentum at the base. Spores elliptical, 13×6µ.
Pileus about 1 in. broad. Stem 2–4 in. long, about 3 lines thick.
Grassy woods. Auburn, Ala. July. Underwood.
A small but pretty species of a yellow color throughout. It is remarkable for its hollow stem, which is suggestive of the specific name. It is referable to the tribe Viscipelles. Peck, Bull. Torrey Bot. Club, Vol. 24, No. 3.
B. sphæros´porus Pk.—globose-spored. (Bulletin Torrey Botanical Club, Vol. XII.) Pileus at first hemispherical, then convex, glabrous, viscid, creamy-yellow, becoming reddish-brown or chestnut color with age. Flesh pale yellowish-brown. Tubes adnate or slightly decurrent, large, angular, pale-yellow, becoming brown, sometimes tinged with green. Stem stout, equal, even or slightly reticulated at the top, the membranous annulus persistent, sometimes partly adhering to the margin of the pileus. Spores globose or broadly elliptical, 8–9µ long.