Boletes of Eastern North America

380 · Boletes of Eastern North America Tylopilus indecisus (Peck) Murrill = Boletus indecisus Peck = Boletus subpunctipes Peck = Tylopilus indecisus var. subpunctipes (Peck) Wolfe = Tylopilus subpunctipes (Peck) A. H. Sm. & Thiers Common name(s): none. Overview: The term indecisus means “undecided.” The cap surface stains dark blackish brown with NH4OH, instantly dark rusty brown to blackish with KOH, and dark gray with FeSO4. The flesh is negative with KOH, NH4OH, or FeSO4. Cap: 5–17 cm wide, convex, becoming broadly convex to nearly plane in age, margin even; surface dry, somewhat velvety, ochraceous brown to pale brown or rarely reddish brown; flesh white, unchanging or slowly staining brownish or pinkish when exposed; odor and taste not distinctive. Pores and tubes: white, becoming pinkish or brownish with age, staining brown when bruised; tubes 6–12 mm deep. Stalk: enlarged downward when young, nearly equal in age, solid; surface dry, whitish when young, becoming pale brown on the lower portion at maturity, staining brown when bruised, reticulate toward the apex; flesh white, staining like the cap flesh. Tylopilus indecisus

Tylopilus · 381 Habitat and season: scattered or in groups near oak or pine, also in mixed broadleaf woods; summer and fall. Distribution and frequency: eastern Canada south to North Carolina, west to Minnesota; occasional. Spore print: pinkish brown to reddish brown. Microscopic features: spores 10–15 × 3–5 µm, narrowly subfusiform, smooth, pale brown. Edibility: edible. Lookalikes: Tylopilus badiceps (p. 371) is similar but has a dark-brown to maroon cap with a beveled to folded margin and a darker stalk with pale to distinctly violaceous tones. Tylopilus ferrugineus (p. 377) is also similar, but it has a darker reddish-brown cap and stalk. Also compare with Tylopilus tabacinus (p. 398), which typically has a larger cap, often grows in grassy areas, and has different macrochemical test reactions. Tylopilus intermedius (A)

382 · Boletes of Eastern North America Tylopilus intermedius A. H. Sm. & Thiers Common name(s): Parchment Bitter Bolete Overview: The term intermedius means “intermediate between two species,” in this case referring to Tylopilus peralbidus (p. 386) and Tylopilus rhoadsiae (p. 391), both of which occur in the southeastern United States. The Parchment Bitter Bolete often typically appears soiled or dirty because of the brown stains that develop on the stalk. Cap: 6–15 cm wide, broadly convex, becoming nearly plane in age, margin incurved when young, with a narrow band of sterile tissue; surface uneven, often wrinkled like parchment, occasionally pruinose, white or whitish when young, occasionally with a pinkish tinge or sometimes ochraceous to tan, developing brownish stains with age; flesh white, firm, very slowly staining dark brown when exposed or where there has been insect damage; odor somewhat pungent or not distinctive; taste bitter. Pores and tubes: white when young, becoming pale tan to pinkish in age, slowly staining brownish when bruised, depressed at the stalk when mature; pores minute, almost appearing like a solid surface on young specimens; tubes 1–1.5 cm deep. Stalk: enlarged to club-shaped or bulbous, solid; surface dry, white or whitish, developing dingy-brownish or yellow-brown stains in age or when handled, weakly to distinctly reticulate (use hand lens); flesh white, staining like the cap flesh. Tylopilus intermedius (B)

Tylopilus · 383 Habitat and season: scattered or in groups under broadleaf trees, especially oak, also reported under pine; summer and fall. Distribution and frequency: New England south to North Carolina, west to Minnesota; infrequent. Spore print: pinkish to pinkish brown. Microscopic features: spores 10–15 × 3–5 µm, nearly oblong, smooth, hyaline to pale brown. Edibility: inedible because of the bitter taste. Lookalikes: Tylopilus peralbidus (p. 386) is similarly colored but lacks reticulation on the stalk. Tylopilus rhoadsiae (p. 391) is also similarly colored, but its flesh does not stain when exposed, and it has prominent, coarse reticulation on the stalk. Boletus pallidus (p. 131) is somewhat similar, but it has whitish to yellow pores that become greenish yellow in age, a faintly or distinctly reticulate stalk, and mild to slightly bitter-tasting flesh. Tylopilus minor (A)

384 · Boletes of Eastern North America Tylopilus minor Singer = Boletus minor (Singer) Murrill Common name(s): Little Bitter Bolete Overview: The term minor means “lesser or smaller,” a reference to this bolete’s stature. The typically small, brown cap, bitter-tasting flesh, and finely to somewhat prominently reticulate stalk with white basal mycelium are reliable field features. Cap: typically 3–8 cm wide, sometimes up to 15.5 cm wide, pulvinate, becoming broadly convex to nearly plane in age, margin even; surface dry, glabrous to finely velvety, pale brown to brown or sometimes dull whitish, often with pinkish tones; flesh white, unchanging when exposed; odor not distinctive; taste bitter. Pores and tubes: white at first, becoming pale brownish pink and often depressed at the stalk in age, not staining when bruised; tubes 4–7(18) mm deep. Stalk: nearly equal or slightly enlarged downward, usually with an abruptly narrowed base, solid; surface dry, with pale to brownish reticulation near the apex or extending to the midportion or sometimes lacking, white to whitish at first, becoming brownish to cinnamon, apex and base whitish, basal mycelium white; flesh white. Habitat and season: solitary, scattered, or in groups in mixed woods or broadleaf forests with oak; late spring, summer, and fall. Tylopilus minor (B)

Tylopilus · 385 Distribution and frequency: New England and New York south to Florida, west to Minnesota and Texas; uncommon. Spore print: pinkish brown. Microscopic features: spores 9–15 × 3–5 µm, fusoid, smooth, yellowish to hyaline. Edibility: inedible because of the bitter taste. Lookalikes: Tylopilus felleus (p. 375) is typically a larger species with coarse, brown reticulation on the stalk. Tylopilus peralbidus (A) Tylopilus peralbidus (B)

386 · Boletes of Eastern North America Tylopilus peralbidus (Snell & Beardslee) Murrill = Boletus peralbidus Snell & Beardslee Common name(s): none. Overview: The term peralbidus means “whitish throughout,” a reference to the color of all parts of this bolete, at least when young. The cap surface stains yellow with KOH and dark blue green with FeSO4 and is negative with NH4OH. The flesh immediately stains dark bluish gray with FeSO4 and pale yellow with KOH or NH4OH. Cap: 4.5–13 cm wide, convex, becoming broadly convex to nearly plane in age, often depressed over the disc, margin even; surface dry, glabrous to slightly velvety, finely cracked in age, white when young, soon becoming ochraceous tan to chamois and finally brownish, staining cinnamon to brown when bruised; flesh white, sometimes staining pale pinkish brown or buff when exposed, often slowly; odor bleach-like or unpleasant; taste bitter. Pores and tubes: whitish when young, becoming buff or tinged pinkish in age, staining brown when bruised, depressed at the stalk in age; tubes 6–10 mm deep. Stalk: equal or tapered in either direction, often with a pointed base, solid; surface dry, smooth, white to brownish or concolorous with the cap, staining brown when bruised or with age; flesh white, staining like the cap flesh. Habitat and season: solitary, scattered, or in groups on shaded lawns, along roads, or in woodlands with oaks or sometimes pines; late spring, summer, and fall. Distribution and frequency: Maryland south to Florida, west to Texas; occasional to locally fairly common. Spore print: pinkish brown. Microscopic features: spores 7–12 × 2.3–3.5 µm, cylindric or cylindric-subclavate, smooth, pale honey yellow. Edibility: unknown. Lookalikes: Tylopilus intermedius (p. 382) is similar, but it has a reticulate stalk. Tylopilus rhoadsiae (p. 391) is also similar, but its pores do not stain when bruised, and its stalk has prominent, coarse reticulation at least over the upper half. Tylopilus rhodoconius (p. 392) has a brownish cap and stalk that stain darker brown when handled and whitish flesh with hyaline marbling.

Tylopilus plumbeoviolaceus (A) Tylopilus plumbeoviolaceus (B)

388 · Boletes of Eastern North America Tylopilus plumbeoviolaceus (Snell & Dick) Singer = Boletus plumbeoviolaceus Snell & E. A. Dick Common name(s): Violet-gray Bolete Overview: The term plumbeoviolaceus means “grayish violaceous,” in reference to this handsome bolete’s overall color. The cap surface stains orange to dull amber with KOH and pale brownish amber with NH4OH or FeSO4. This medium to large bolete is one of several in the genus Tylopilus that have flesh that tastes exceedingly bitter. The combination of a brownish to purplish-brown cap, a purple stalk, and bitter flesh makes this bolete easy to recognize. Cap: 4–15 cm wide, convex to broadly convex with a narrow sterile margin, becoming nearly plane in age; surface glabrous, smooth, shiny, at times becoming cracked, brownish to grayish brown or dull cinnamon, at times tinged with purplish areas, especially toward the margin, or entirely purple when young; flesh firm when fresh, white, not staining when cut or bruised, insect-damaged areas becoming brown; odor slightly pungent or not distinctive; taste very bitter. Pores and tubes: dull white when young, becoming very pale brownish to pinkish tan with age, not staining when bruised or just barely bruising very lightly pinkish brown, depressed at the stalk at maturity; pores minute; tubes 4–18 mm deep. Stalk: nearly equal or enlarged downward, solid; surface dry, purple with white mycelium at the base when young, at times becoming grayish purple or purplish brown, smooth and glabrous except for a narrow zone of reticulation at the apex; flesh concolorous with the cap flesh, insect-damaged areas especially becoming brown. Habitat and season: solitary or in small groups in broadleaf woods with oak; early summer and early fall. Distribution and frequency: widely distributed; fairly common. Spore print: purplish brown. Microscopic features: spores 10–13 × 3–4 µm, ellipsoidal, smooth, pale brown. Edibility: inedible due to strongly bitter flesh. Lookalikes: Tylopilus plumbeoviolaceus is not likely to be confused with any bolete other than the equally bitter Tylopilus violatinctus (p. 402), which differs by having a paler grayish-lilac to pinkish-lilac cap, a pale-lilac stalk that is white at the apex, and smaller spores.

Tylopilus · 389 Tylopilus porphyrosporus (Fr. & Hök) A. H. Sm. & Thiers = Boletus pseudoscaber Secr. ex Singer = Porphyrellus porphyrosporus (Fr. & Hök) E. J. Gilbert = Porphyrellus pseudoscaber (Secr.) Singer = Tylopilus nebulosus (Peck) Wolfe = Tylopilus pseudoscaber (Secr.) A. H. Sm. & Thiers Common name(s): Dark Bolete Overview: The term porphyrosporus means “purple-red spores.” The cap surface stains mahogany red with KOH or NH4OH and is negative with FeSO4. The flesh stains dull orange with KOH and green with FeSO4 and is negative with NH4OH. Much confusion and contradiction occur in the literature concerning this species. Some authors have used the presence or absence of a blue staining reaction of the flesh and pores or growth with conifers rather than with broadleaf trees as a basis for naming different species. Specimens wrapped in waxed paper for an hour or so sometimes stain the paper blue. Cap: 5–15 cm wide, convex, becoming broadly convex to nearly plane in age, margin even; surface dry, somewhat velvety, sometimes finely to conspicuously cracked in age, dark brown to olive brown or dark vinaceous brown, sometimes staining darker brown when bruised, usually paler at the margin; flesh white, sometimes rapidly or slowly staining blue when exposed Tylopilus porphyrosporus

390 · Boletes of Eastern North America and then staining reddish brown and finally grayish brown to grayish black; odor pungent, clove-like or resembling coal tar or burned rubber or unpleasant; taste weakly bitter to unpleasant or not distinctive. Pores and tubes: pinkish brown to dark reddish brown or dark brown, depressed at the stalk in age, bruising dark reddish brown, sometimes with dark greenish-blue stains; tubes 1.3–2 cm deep, concolorous with the pores or paler, typically staining blue when bruised. Stalk: enlarged downward or nearly equal; surface dry, scurfy-punctate, concolorous with the cap, often with a whitish base, with or without reticulation at the very apex; flesh concolorous with and staining like the cap flesh, sometimes with a strong odor of chlorine in the base. Habitat and season: solitary, scattered, or rarely in groups in broadleaf woods, conifer forests, or mixed woods, sometimes on well-decayed logs and stumps; summer and fall, also winter in the southern part of its range. Distribution and frequency: widely distributed throughout eastern North America; uncommon to occasional. Spore print: dark reddish brown. Microscopic features: spores 12–18 × 6–7.5 µm, ellipsoidal, smooth, pale brown. Edibility: unknown. Lookalikes: Tylopilus sordidus (p. 396) has a similarly colored cap and stalk, but its pores are whitish to grayish buff when young, and it has smaller spores and different macrochemical test reactions. Tylopilus rhoadsiae (A)

Tylopilus · 391 Tylopilus rhoadsiae (Murrill) Murrill = Boletus rhoadsiae (Murrill) Murrill = Gyroporus rhoadsiae Murrill Common name(s): Pale Bitter Bolete Overview: The white to whitish cap; white, unchanging, and bitter flesh; white pores that become dull pinkish in age; and a white to whitish, prominently reticulate stalk are this distinctive bolete’s key identifying features. The cap surface stains pale yellow with KOH or NH4OH and gray with FeSO4. Cap: 6–15 cm wide, convex, becoming broadly convex to nearly plane in age, margin even; surface dry, somewhat velvety to glabrous, sometimes shiny, white to whitish, often with buff, grayish-buff, pinkish, or pinkish-tan tinges or sometimes becoming tan, pinkish brown, or golden brown overall in age; flesh white, unchanging when exposed; odor not distinctive; taste bitter. Pores and tubes: white when young, becoming dull pinkish in age, unchanging when bruised, depressed at the stalk in age; tubes 9–20 mm deep. Stalk: nearly equal or enlarged above a pinched base, solid, basal mycelium white; surface dry, white or concolorous with the cap, prominently reticulate nearly overall or at least on the upper half; flesh concolorous with the cap flesh. Habitat and season: scattered or in groups near or under pines or oaks; summer and fall, also winter in the southern part of its range. Distribution and frequency: New England south along the coastal plain to Florida, west to Texas; fairly common along the Gulf Coast and increasingly uncommon northward. Tylopilus rhoadsiae (B)

392 · Boletes of Eastern North America Spore print: pinkish to brownish vinaceous. Microscopic features: spores 11–13.5 × 3.5–4.5 µm, oblong-ellipsoidal, smooth, hyaline to pale yellow. Edibility: unpalatable because of the bitter taste. Lookalikes: Tylopilus intermedius (p. 382) is similarly colored, but its pores slowly stain brownish when bruised, and it has finer reticulation on its stalk. Tylopilus peralbidus (p. 386) is also similarly colored, but its stalk lacks reticulation. Tylopilus rhodoconius (p. 392) has a darker-brown cap and a stalk that stains brown when handled, and its flesh is white to creamy white with hyaline marbling. Tylopilus rhodoconius T. J. Baroni, Both & Bessette = Tylopilus peralbidus var. rhodoconius Singer Common name(s): none. Overview: The white to creamy-white, soft flesh with hyaline marbling is distinctive. The cap surface slowly stains pale yellow brown with KOH or NH4OH and bluish green to bluish gray with FeSO4. Cap: 4–14 cm wide, hemispheric, becoming broadly convex to nearly plane in age, margin incurved at first and remaining so well into maturity, with a narrow band of sterile tissue; surface dry, finely velvety, delicately cracked at maturity, pale ochraceous to brownish orange at first, becoming pale brown and then darker brown with a paler margin, staining dark brown when handled or bruised; flesh firm when young, soft at maturity, white Tylopilus rhodoconius

Tylopilus · 393 to pale creamy white with hyaline marbling, slowly staining pale pinkish and then dingy pinkish red when exposed; odor faintly of chlorine or not distinctive; taste mild at first and then very bitter. Pores and tubes: white to whitish when young, becoming pale pinkish brown in age, staining dull brown and then darker brown when bruised; tubes 6–10 mm deep. Stalk: nearly equal or enlarged downward, tapered to a point at the base, often with a short, root-like projection, solid; surface dry, nearly glabrous, white near the apex, gradually yellow brown to reddish brown downward, or concolorous with the cap, staining brown to dark brown when handled, with white basal mycelium; flesh concolorous with and staining like the cap flesh. Habitat and season: scattered or in groups under oak, pine, or in mixed oak, beech, and pine woods; summer and fall. Distribution and frequency: Cape Cod, Massachusetts, and Florida, distribution limits yet to be established; rare to uncommon. Spore print: pink to reddish gray. Microscopic features: spores 8.4–13 × 2–3.5 µm, cylindric, smooth, hyaline. Edibility: unknown. Lookalikes: Tylopilus intermedius (p. 382) has a paler cap and stalk, white flesh that lacks hyaline marbling, and a reticulate stalk. Tylopilus peralbidus (p. 386) has a paler cap and stalk and white flesh that lacks hyaline marbling. Tylopilus rhoadsiae (p. 391) has a paler cap and stalk and white flesh that lacks hyaline marbling, and its stalk has prominent reticulation. Tylopilus rubrobrunneus (A)

Tylopilus rubrobrunneus (B) Tylopilus rubrobrunneus (C)

Tylopilus · 395 Tylopilus rubrobrunneus Mazzer & A. H. Sm. Common name(s): Reddish-brown Bitter Bolete Overview: The term rubrobrunneus means “reddish brown.” During wet periods, this species is commonly attacked by a white mold. The purple areas of the cap surface bleach pinkish brown with KOH or NH4OH and are negative with FeSO4. Cap: 8–30 cm wide, broadly convex, becoming nearly plane and occasionally slightly depressed in age, margin even, incurved to inrolled at first; surface dry, glabrous or nearly so, sometimes becoming cracked in age, dark to bright purple when young, becoming purple brown, dark reddish brown, dull brown, or cinnamon in age; flesh white, unchanging or slowly staining brown when cut or bruised; odor not distinctive; taste very bitter. Pores and tubes: whitish to very pale brownish at first, becoming dingy pinkish brown at maturity, staining brown when bruised; tubes 8–20 mm deep. Stalk: nearly equal or enlarged downward, solid; surface dry, white to brown, developing olive or olive-brown stains from the base upward as specimens mature or overall when handled, glabrous or with fine reticulation at the apex; flesh white, staining like the cap flesh. Habitat and season: scattered, in groups, or caespitose in broadleaf woods with beech or oak, also in mixed oak and pine woods or with hemlock; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; fairly common. Spore print: reddish brown to dull pinkish brown. Microscopic features: spores 10–14 × 3–4.5 µm, suboblong to nearly fusoid, smooth, pale brown. Edibility: unpalatable because of the bitter taste. Lookalikes: The equally bitter-tasting Tylopilus violatinctus (p. 402) is similar but has a pale-purplish to grayish-violet or pale-brown cap, and it does not develop olive-brown stains on the stalk. Tylopilus felleus (p. 375) has less-pronounced purplish tones on the cap. Its stalk has more prominent reticulation and lacks olive stains.

396 · Boletes of Eastern North America Tylopilus sordidus (Frost) A. H. Sm. & Thiers = Boletus sordidus Frost = Porphyrellus cyaneotinctus (A. H. Sm. & Thiers) Singer = Porphyrellus fumosipes (Peck) Snell = Porphyrellus pseudoscaber ssp. cyaneotinctus Singer = Porphyrellus sordidus (Frost) Snell = Porphyrellus umbrosus (G. F. Atk.) Singer, J. Garcia & L. D. Gómez = Tylopilus cyaneotinctus A. H. Sm. & Thiers = Tylopilus fumosipes (Peck) A. H. Sm. & Thiers = Tylopilus umbrosus (G. F. Atk.) A. H. Sm. & Thiers Common name(s): none. Overview: This small- to medium-size dark bolete is recognizable by its typically cracked cap and dramatic bluish-green bruising of the pores and cap flesh. The term sordidus means “dirty or smoky,” a reference to this bolete’s overall colors. When its flesh is wrapped in waxed paper for several minutes, it stains the paper a dark blue-green color. Cap: 4.5–13 cm wide, convex, becoming broadly convex to nearly plane in age, margin with a band of sterile tissue when young, becoming even at maturity; surface dry, glabrous to somewhat velvety, becoming cracked in age, gray brown to olive brown or dark brown, often with dark-greenish Tylopilus sordidus

Tylopilus · 397 or bluish tints along the margin; flesh whitish, staining blue green when exposed, sometimes with reddish tints; odor slightly pungent or not distinctive; taste unpleasant or not distinctive. Pores and tubes: whitish to grayish buff when young, becoming pinkish brown and then reddish brown to yellow brown, staining dark blue to dark blue green and then dark brownish red when bruised; tubes 6–20 mm deep. Stalk: slightly enlarged downward or nearly equal, solid; surface dry, minutely scurfy, brownish with much darker longitudinal streaks, typically paler toward the upper portion and whitish at the base, with greenish or bluish-green tints near the apex; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary, scattered, or in groups under broadleaf trees, especially oak, and under various conifers; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; occasional. Spore print: reddish brown. Microscopic features: spores 10–14 × 4–6 µm, subellipsoidal, smooth, pale brown. Edibility: unknown. Lookalikes: Tylopilus porphyrosporus (p. 389) has a similarly colored cap and stalk, but its pores are dark reddish brown to dark brown or blackish brown in all stages, and it has larger spores. Tylopilus tabacinus (A)

398 · Boletes of Eastern North America Tylopilus tabacinus (Peck) Singer = Boletus tabacinus Peck = Ceriomyces tabacinus (Peck) Murrill = Tylopilus tabacinus var. amarus Singer = Tylopilus tabacinus var. dubius Singer Common name(s): none. Overview: The term tabacinus means “color of tobacco.” This bolete’s cap surface stains rusty brown to dark maroon with KOH, vinaceous with NH4OH, and pale olive gray with FeSO4. Specimens with bitter-tasting flesh were previously identified as var. amarus. Cap: 4.5–18 cm wide, obtuse when young, becoming broadly convex to nearly plane in age, margin even and wavy; surface dry, smooth, slightly velvety, becoming finely cracked in age, yellow brown to orange brown or tobacco brown; flesh white, usually slowly staining purplish buff or pinkish buff when exposed, often brown at maturity; odor variously described as fruity, fishy, pungent, or not distinctive; taste slightly bitter or not distinctive. Pores and tubes: whitish or sometimes brown at first, becoming brown to yellow brown, with darker-brown patches and stains, usually depressed at the stalk in age; tubes 1–1.5 cm deep. Tylopilus tabacinus (B)

Tylopilus · 399 Stalk: enlarged to bulbous when young, becoming nearly equal in age, solid; surface dry, concolorous with the cap, prominently reticulate at least over the upper portion, usually glabrous on the lower portion; flesh concolorous with the cap flesh or sometimes burgundy brown near the base, staining like the cap flesh. Habitat and season: scattered or in groups in woods and at their edges or around trees in lawns, usually with oak and pine; summer and fall. Distribution and frequency: New England south along the coastal plain to Florida, west to Texas; occasional to locally fairly common. Spore print: pinkish brown to reddish brown. Microscopic features: spores (10)12–14(17) × 3.5–4.5 µm, fusoid to ellipsoidal, smooth, hyaline to pale honey yellow; pleurocystidia 45–60 × 6.5–12.5 µm, lanceolate to narrowly fusoid-ventricose; cheilocystidia absent. Edibility: unknown. Lookalikes: Tylopilus indecisus (p. 380) usually has a smaller cap, typically occurs in woodlands, and has different macrochemical test reactions. Tylopilus felleus (p. 375) is similar, but its pores are white to brown, not pinkish to vinaceous, and it has very bitter-tasting flesh. Boletus durhamensis (p. 99) has an olivaceous gray-brown spore print, finer reticulation on the upper portion of the stalk or at least near the apex, mild-tasting flesh, and cheilocystidia. Tylopilus variobrunneus (A)

400 · Boletes of Eastern North America Tylopilus variobrunneus Roody, A. R. Bessette & Bessette Common name(s): Variable Brown-net Bolete Overview: The term variobrunneus means “various shades of brown,” a reference to the color of this bolete’s cap, stalk, and staining reactions of the pores and flesh. When this handsome bolete is very young, it has a compact stature and firm flesh, and the stalk and reticulation can be totally white, although brown coloration is typical. The cap surface stains grayish green with FeSO4 and reddish brown to orange brown with KOH or NH4OH. The flesh stains grayish green with FeSO4 and is negative with KOH or NH4OH. Cap: 4–12 cm wide, convex, becoming broadly convex to nearly plane in age, margin incurved at first, with a narrow band of sterile tissue when young, becoming decurved and even at maturity; surface dry, somewhat velvety and dark olive brown to greenish brown or blackish brown when young, becoming nearly glabrous and dull medium brown to chestnut brown at maturity, remaining darker over the disc and fading to pale chestnut brown in age; flesh dull white, slowly staining dull pinkish rose to pale brownish pink when exposed, insect-damaged areas staining dark brown; odor not distinctive; taste mild or slightly bitter. Pores and tubes: dull white to creamy white at first, becoming yellow brown to brownish pink, depressed at the stalk in age, staining brown to brownish rose or pinkish cinnamon, sometimes slowly, when bruised; tubes 5–13 mm deep. Tylopilus variobrunneus (B)

Tylopilus · 401 Stalk: enlarged downward or nearly equal, usually with a pinched base, solid; surface dry, dull white on the upper portion, becoming pale brown on the lower portion, dark brown toward the base, basal mycelium white, with prominent reticulation over the upper two-thirds or at least over the upper half; reticulation white near the apex when young, brown below; flesh concolorous with and staining like the cap flesh, blackish brown around larval tunnels. Habitat and season: solitary, scattered, or in groups under oaks or in mixed oak–pine woods; summer and fall. Distribution and frequency: New England south to Florida, west to Minnesota and Mississippi; occasional to locally fairly common. Spore print: dull pinkish brown to cocoa powder brown. Microscopic features: spores 9–13 × 3–4.5 µm, subfusiform to subellipsoidal, smooth, pale ochraceous. Edibility: edible but with an unpleasant aftertaste. Lookalikes: Tylopilus variobrunneus is sometimes confused with Tylopilus felleus (p. 375), which has very bitter-tasting flesh. Tylopilus badiceps (p. 371) is similar but has a reddish-brown to maroon cap, typically with a beveled margin; a darker-brown stalk that usually lacks reticulation; and pores that remain white for a long time and then become dingy white to brownish, not pinkish, at maturity. Tylopilus violatinctus (A)

402 · Boletes of Eastern North America Tylopilus violatinctus T. J. Baroni & Both Common name(s): Pale Violet Bitter Bolete Overview: The term violatinctus means “tinged violet.” The cap surface stains yellowish to brownish yellow with NH4OH and dingy pale yellowish to amber with KOH and is negative with FeSO4. The flesh stains yellow with FeSO4 and then quickly develops a blue ring around the yellow. Cap: 7.5–14 cm wide, hemispheric, becoming broadly convex to nearly plane in age, margin strongly incurved at first, with a narrow band of sterile tissue; surface dry, somewhat velvety when young, becoming nearly glabrous when mature, sometimes cracked in age, grayish violet to bluish violet when young, becoming pale purplish, purplish pink, or tan to dull brown in age, staining rusty violet to dark violet when bruised; flesh white, unchanging or becoming very pale slate-colored when exposed; odor pungent or not distinctive; taste intensely bitter. Pores and tubes: white to dull pink at first, becoming brownish, unchanging when bruised, typically depressed at the stalk in age; tubes up to 1.5 cm deep. Stalk: enlarged downward or nearly equal, sometimes with a bulbous base, solid; surface dry, nearly glabrous, concolorous with the cap or paler when young, becoming brown in age with a white apex and base, at times Tylopilus violatinctus (B)

Tylopilus · 403 staining dull yellow to yellow brown when bruised, sometimes with inconspicuous reticulation at the apex; flesh concolorous with the cap flesh. Habitat and season: solitary, scattered, or in groups under oak and pine, also with beech, spruce, or hemlock; late spring, summer, and fall. Distribution and frequency: New England and New York south to Florida, west to Minnesota and Mississippi; occasional. Spore print: reddish brown. Microscopic features: spores 7–10 × 3–4 µm, subfusiform, smooth, pale yellow. Edibility: unknown but too bitter to be of interest. Lookalikes: Tylopilus plumbeoviolaceus (p. 388) is similar but has a dark-purple stalk. Tylopilus rubrobrunneus (p. 395) is typically more robust, has a purple-brown to vinaceous-brown cap that fades to pinkish cinnamon in age, and develops olive-brown stains on its stalk, especially when handled. Tylopilus williamsii (A)

Tylopilus williamsii (B) Tylopilus williamsii (C)

Veloporphyrellus · 405 Tylopilus williamsii Singer & J. Garcia Common name(s): none. Overview: This bolete was named in honor of Florida mycologist Robert S. Williams (1939–2014), who first collected and described it. The dark magenta to purple-violet or brownish-purple cap, bitter flesh, and white to pinkish pores that bruise yellowish are its reliable field features. The cap surface stains orange yellow with KOH and orange with NH4OH. The flesh stains greenish with FeSO4. Cap: 4–10 cm wide, hemispheric when young, becoming broadly convex to nearly plane in age, margin even, incurved at first; surface dry, somewhat velvety, often uneven in age, dark magenta to purple violet or brownish purple when young, fading to pinkish gray to pale yellow brown; flesh white, unchanging when exposed; odor not distinctive; taste bitter. Pores and tubes: white at first, becoming pale pinkish at maturity, staining yellowish to yellow brown when bruised; tubes 1–1.5 cm deep. Stalk: nearly equal overall, solid; surface dry, glabrous, pale yellow to grayish, often streaked with beige and grayish orange; flesh concolorous with the cap flesh. Habitat and season: scattered or in groups under oaks; summer and fall. Distribution and frequency: southeastern coastal Georgia and Florida, west to Mississippi, distribution limits yet to be established; rare to uncommon. Spore print: pink. Microscopic features: spores 7.5–11 × 3.5–4.5 µm, fusoid to ellipsoid, smooth, hyaline to pale yellow. Edibility: inedible because of the bitter taste. Lookalikes: Tylopilus plumbeoviolaceus (p. 388) is similar, but it has a violet or purple stalk, which is sometimes reticulate at the apex. Tylopilus violatinctus (p. 402) has a paler and more lilac cap that bruises violet, a concolorous stalk with a white apex, and a base that typically stains yellowish when bruised. Genus Velopor ph yr ellus L. D. Gómez & Singer The genus Veloporphyrellus was erected in 1984 to accommodate species formerly classified in two genera, Boletus and Tylopilus. Veloporphyrellus is a genus known from North and Central America, Africa, and southeastern Asia. Only one species is currently known to occur in eastern North America. The distinguishing features of the genus are the pinkish to grayish-pink pores, the membranous veil remnants that hang on the cap margin, a trichodermium-like cuticle, and smooth spores. These boletes have caps that are typically dry and shaggy or scaly, with soft-textured white flesh. The pores are white at first and become grayish pink to pinkish brown at maturity.

Veloporphyrellus conicus (A) Veloporphyrellus conicus (B)

Xanthoconium · 407 Veloporphyrellus conicus (Ravenel) B. Ortiz, Yan C. Li & Zhu L. Yang = Fistulinella conica var. conica (Ravenel) Pegler & T. W. K. Young = Mucilopilus conicus (Ravenel) Wolfe = Tylopilus conicus (Ravenel) Beardslee Common name(s): Conical Shaggy-capped Bolete Overview: The Conical Shaggy-capped Bolete is an easy-to-recognize southern species. It is distinctive for its bluntly conical yellowish floccose-shaggy cap and smooth, slender stalk. The term conicus means “cone-shaped,” a reference to the shape of the young cap. Cap: 2.5–9.5 cm wide, bluntly conical when young, becoming convex in age; margin fringed with thin flaps of membranous veil tissue, at least when young; surface dry, shaggy or scaly when young and often developing a network of ridges and small depressions in age, pinkish tan to golden yellow, yellow brown or salmon-tinged, with white flesh showing between the scales or beneath the ridges; flesh white, not staining when cut; odor fruity or not distinctive; taste not distinctive. Pores and tubes: white when young, becoming grayish pink to pinkish brown at maturity; tubes 8–14 mm deep. Stalk: slender, nearly equal, often curved, solid; surface dry, smooth or minutely wrinkled, rarely reticulate, white or yellow, sometimes with pinkish tones especially toward the midportion; flesh concolorous with the cap flesh. Habitat and season: solitary or scattered under pine and in mixed woods, often in bottomlands along streams; summer and fall. Distribution and frequency: North Carolina south to Florida, western limits yet to be established; occasional to fairly common. Spore print: pinkish brown to reddish brown. Microscopic features: spores 14–21 × 4–6 µm, elongate-fusoid, smooth, hyaline to honey yellow, pseudoamyloid in Melzer’s. Edibility: edible. Lookalikes: Fistulinella conica var. reticulata (Wolfe) Singer (not illustrated), described from Florida, is nearly identical but has prominent reticulation on its stalk. Genus Xan t hoconium Singer The genus Xanthoconium was erected in 1944 to accommodate species that produce a yellowish to ochraceous, bright yellow-brown, or bright rusty-brown spore deposit, formerly classified in the genus Boletus. The name Xanthoconium means “yellow cone,” a reference to the spore color and shape. It is a small genus, with only three species that occur in eastern North America. They have white to yellow pores that do not bruise blue and flesh that does not stain when exposed. Some species have reticulation on the stalk.

Xanthoconium affine (A) Xanthoconium affine (B)

Xanthoconium · 409 Xanthoconium affine (Peck) Singer = Boletus affinis Peck = Xanthoconium affine var. affine (Peck) Singer = Xanthoconium affine var. maculosus (Peck) Singer = Xanthoconium affine var. reticulatum (A. H. Sm.) Wolfe Common name(s): none. Overview: The term affine means “related,” referring to a similarity with Boletus edulis (p. 101). The cap surface stains reddish brown with NH4OH and is negative with KOH or NH4OH. The key identification features include Xanthoconium affine (C)

410 · Boletes of Eastern North America the brown cap that sometimes has pale-yellow spots, white flesh that does not stain when exposed, white to yellow-brown pores, and a whitish stalk with brownish streaks and with or without reticulation. Cap: 4–11.5 cm wide, convex to broadly convex, becoming nearly plane in age, margin even; surface dry, somewhat velvety, smooth or wrinkled, dark brown to chestnut brown or ocher brown, sometimes with white to pale-yellow spots or patches; flesh white, unchanging when exposed; odor and taste not distinctive. Pores and tubes: white at first, becoming yellowish to dingy yellow brown, bruising dull yellow to brownish, depressed at the stalk in age; tubes 6–20 mm deep. Stalk: nearly equal or tapered in either direction, solid; surface smooth or with sparse to conspicuous brown reticulation, dry, whitish, often with brownish streaks on the middle portion or base; flesh concolorous with the cap flesh. Habitat and season: usually in groups, sometimes in caespitose clusters, or scattered in broadleaf woods, especially with oak or beech, also under pines; spring, summer, and fall. Distribution and frequency: widely distributed throughout eastern North America; common. Spore print: bright yellow brown to rusty ochraceous. Microscopic features: spores (9)12–16 × 3–5 µm, narrowly ventricose to nearly cylindrical, smooth, yellowish. Edibility: edible and good when young. Lookalikes: Xanthoconium purpureum (p. 412) is very similar, except it has a purplish-red to maroon cap. Xanthoconium chattoogaense Wolfe (not illustrated) is known only from the Chattooga River region in the Nantahala National Forest of North Carolina. This bolete grows in mixed woods with oaks, red maple, and rhododendron. It has a somewhat waxy, golden-brown cap; white flesh with a disagreeable odor that is reminiscent of rotting meat; and a thick, obclavate, yellowish-white stalk with a brownish apex.

Xanthoconium purpureum (A) Xanthoconium purpureum (B)

412 · Boletes of Eastern North America Xanthoconium purpureum Snell & E. A. Dick = Boletus purpureofuscus A. H. Smith Common name(s): none. Overview: The term purpureum means “purplish,” a reference to this bolete’s cap colors. The cap surface stains greenish blue with NH4OH and is negative with KOH or FeSO4. The flesh is negative with NH4OH, KOH, or FeSO4. Cap: 3–11.5 cm wide, rounded to convex, becoming broadly convex to nearly plane in age, margin even, incurved at first; surface dry, glabrous, sometimes wrinkled, dark red to purple red or maroon, sometimes with pale-brownish tints; flesh whitish, unchanging when exposed; odor and taste not distinctive. Pores and tubes: whitish at first, becoming ochraceous yellowish to rusty ochraceous with age, staining brownish when bruised, depressed at the stalk at maturity; tubes 8–16 mm deep. Stalk: nearly equal or slightly enlarged downward, solid; surface dry, smooth, pale yellow to brownish yellow, usually with reddish or brownish streaks, base white, weakly reticulate at the apex or at times more prominently reticulate, sometimes longitudinally striate on the upper portion; flesh concolorous with the cap flesh. Habitat and season: solitary or scattered in broadleaf woods under oak or in mixed oak and pine woods; spring, summer, and fall. Distribution and frequency: throughout northeastern North America, south to Georgia; fairly common. Spore print: rusty ochraceous to yellow ocher. Microscopic features: spores 8–14 × 3–4 µm, oblong-ellipsoid to subfusiform, smooth, pale yellow. Edibility: edible and good. Lookalikes: This bolete is sometimes confused with Xanthoconium affine (p. 409), but the latter lacks reddish to purplish tones on the cap and stains reddish brown when NH4OH is applied. Boletus separans (p. 153) has a paler cap and stalk with lilac tones, and its pores do not stain brownish when bruised.

Xanthoconium · 413 Xanthoconium stramineum (Murrill) Singer = Boletus stramineus (Murrill) Murrill Common name(s): none. Overview: The cap of Xanthoconium stramineum stains bluish gray with FeSO4, stains quickly salmon pink with KOH and then fades on dark areas, and is negative with NH4OH. The term stramineum means “straw-colored,” alluding to the cap color. Cap: 4–9 cm wide, convex, becoming broadly convex to nearly plane in age, margin incurved at first, with a narrow band of sterile tissue; surface dry, glabrous and smooth when young, sometimes becoming cracked and uneven with age, white at first, becoming whitish to pale straw-colored or tinged brownish; flesh white, unchanging or slowly staining pinkish brown when exposed; odor variously described as slightly fruity, unpleasant, or not distinctive; taste somewhat bitter or not distinctive. Pores and tubes: white to whitish at first, becoming buff to yellowish buff or pale yellow brown in age, unchanging when bruised; tubes 3–10 mm deep. Stalk: enlarged downward or nearly equal, usually with a swollen base, solid; surface dry, glabrous, white to whitish, not staining when bruised; flesh white, staining like the cap flesh. Xanthoconium stramineum

414 · Boletes of Eastern North America Habitat and season: solitary, scattered, or in groups on sandy soil or in grassy areas, under oak and pine; summer and fall. Distribution and frequency: coastal plain of North Carolina south to Florida, west to Texas; occasional to fairly common. Spore print: brownish yellow to yellowish rusty brown. Microscopic features: spores 10–15 × 2.5–4 µm, cylindrical, smooth, yellowish to hyaline. Edibility: reported to be edible but in our experience sour, bitter, and unpleasant. Lookalikes: This southern bolete can be confused with Boletus albisulphureus (p. 86), which has a reticulate stalk. Gyroporus subalbellus (p. 215) is similar but has a brittle stalk that becomes hollow at maturity. Xanthoconium montaltoense Wolfe (not illustrated) is known only from the Mixhaux State Forest in south-central Pennsylvania. It has a white to pale-cream cap that darkens to ocher or pale yellow gold in age, a stalk that is concolorous with the cap, and white flesh, and it grows under birch and hemlock. Genus Xerocomellus Šutara The genus Xerocomellus was erected in 2008 to accommodate fairly small boletes that have short, broad, and encrusted cuticular cap hyphae. Species in this genus have soft flesh and caps that often become cracked. Microscopically, they have dense, parallel, nondivergent hyphal trama and short to elongate, ellipsoidal to oblong, or subfusiform spores. In some species, the spores are longitudinally striate or are smooth and sometimes truncate. The genus Xerocomus is very similar to Xerocomellus, but species in Xerocomus have long, smooth, nonencrusted cuticular cap hyphae and spores with a bacillate shape. A useful field character for recognizing species of Xerocomellus and Xerocomus is a tendency of the tubes to split lengthwise when cut or torn owing to their parallel, nondivergent hyphal trama. The tubes of species in other bolete genera, such as Boletus, remain intact when cut or torn because they have strongly divergent hyphal trama. There are no significant macroscopic characteristics that differentiate species of Xerocomellus from species of Xerocomus. Only a few species of Xerocomellus are known to occur in eastern North America.

Xerocomellus chrysenteron (A) Xerocomellus chrysenteron (B)

416 · Boletes of Eastern North America Xerocomellus chrysenteron (Bull.) Šutara = Boletus chrysenteron (Bulliard) Fries = Xerocomus chrysenteron (Bulliard) Quélet Common name(s): Red-cracked Bolete Overview: The cap surface stains dark brown to blackish with KOH, olive with FeSO4, and brownish or negative with NH4OH. During extended periods of wet weather, this common bolete is often infected with the parasitic mold Hypomyces chrysospermus, which envelops the fruitbody with a white to golden-yellow coating. The term chrysenteron means “gold intestine,” possibly an obscure reference to the meandering pattern of the cracks on the cap surface. Cap: 3–7.5 cm wide, convex, becoming broadly convex to nearly plane; surface dark olive to olive brown or grayish brown, often with a reddish zone at the margin, velvety at first, soon becoming cracked with red to pinkish color in the cracks; flesh soft, white to pale yellow, often with a pinkish-red zone beneath the cuticle, slowly staining blue when exposed; odor and taste not distinctive. Pores and tubes: yellow, becoming olivaceous with age, bruising greenish blue, sometimes slowly, typically depressed at the stalk with age; tubes 2–10 mm deep. Xerocomellus truncatus

Xerocomellus · 417 Stalk: slender, more or less equal to slightly enlarged downward, solid; surface dry, finely granular to somewhat scurfy, sometimes with longitudinal streaks, yellow on the upper portion, usually reddish near the base, with white basal mycelium, at times staining bluish green when handled; flesh white to pale yellow, staining pinkish red and sometimes slowly and erratically staining blue. Habitat and season: solitary to scattered in broadleaf and conifer woods, also on roadside banks; late spring, summer, and fall. Distribution and frequency: eastern Canada south to North Carolina, west to Minnesota and Texas; fairly common but rarely found in large numbers. Spore print: olive brown. Microscopic features: spores 9–13 × 3.5–4.5 µm, oblong, smooth, pale brown. Edibility: edible but poor. Lookalikes: Xerocomellus truncatus (Singer, Snell & E. A. Dick) Klofac = Boletus truncatus (Singer, Snell & E. A. Dick) Pouzar (see photo, p. 416) is nearly identical, but many of its spores are distinctly truncated and measure 10–15 × 5–7 µm. Compare with Xerocomellus intermedius (p. 419), which has a dry, somewhat velvety, red to rose-red or olivaceous cap that becomes cracked in age. Like Xerocomellus chrysenteron, the cap of Xerocomellus intermedius typically shows pinkish tints in the fissures as it ages, and its flesh stains blue when exposed. Also compare with Boletellus chrysenteroides (p. 78), which often grows on decaying logs and stumps or at the base of standing trunks. It has a darker cap that becomes cracked but does not show reddish in the fissures. Boletus subtomentosus var. subtomentosus (p. 165) is somewhat similar but does not show reddish in the cap fissures. It has yellow pores that bruise slightly greenish blue, if at all. Boletus ferrugineus (p. 105) lacks reddish tinges in the cap fissures, and the cap surface displays a green flash with NH4OH and then stains reddish brown. Boletus subdepauperatus (not illustrated), reported from New England and New York west to Michigan, has a dingy olive-brownish to dingy yellow-brown cap that is finely cracked in age, whitish flesh that stains blue when exposed, yellow pores that stain blue when bruised, a yellowish-brown pruinose stalk, and spores that measure 9–12 × 4.5–5 µm. It grows in broadleaf woods.

Xerocomellus intermedius (A) Xerocomellus intermedius (B)

Xerocomellus · 419 Xerocomellus intermedius (A. H. Sm. & Thiers) Svetasheva, Simonini & Vizzini = Boletellus intermedius A. H. Sm. & Thiers Common name(s): none. Overview: The term intermedius means “intermediate between two species,” referring to this bolete’s very similar appearance to both Boletellus pseudochrysenteroides (p. 80) and Xerocomellus chrysenteron (p. 416). The key identification features include the rose-red cap when young, pink tints showing in a cracked cap cuticle, blue-staining pores, and striate spores that measure 9–12 × 4–5 µm. Cap: 4–10 cm wide, convex, becoming broadly convex to nearly plane, margin even, incurved when young; surface dry, subtomentose, becoming cracked in age, red to rose red or soon grayish to olive brown or olive gray at maturity, typically showing pink tints in the cracks in age; flesh yellow, staining blue when exposed; odor and taste not distinctive. Pores and tubes: bright yellow to yellow when young, becoming brownish yellow to reddish brown in age, staining blue and then slowly brown when bruised; tubes 7–12 mm deep. Stalk: nearly equal or slightly enlarged in either direction, solid; surface dry, yellow at the apex, punctate with rhubarb-red dots and points over a yellow ground color below the apex, usually with longitudinal ribs, with a white to pale-yellow basal mycelium; flesh concolorous with and staining like the cap flesh. Habitat and season: scattered or in groups under broadleaf trees or in mixed woods with oak and pine; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; occasional. Spore print: olive to olive brown. Microscopic features: spores 9–12 × 4–5 µm, subellipsoidal to fusoid, weakly longitudinally striate, pale brown. Edibility: unknown. Lookalikes: Xerocomellus chrysenteron (p. 416) has a dark-olive to olivebrown cap that becomes cracked in age, with reddish tinges in the cracks, and smooth spores. Boletellus pseudochrysenteroides (p. 80) grows on the ground in broadleaf woods, especially with beech or oak. When young, it has a dark rose-red to red-brown cap that typically becomes olivaceous and develops prominent cracks as it ages. It has whitish to pale-yellow flesh that quickly stains blue when exposed; its stalk base is sometimes coated with yellowish mycelium; and it has larger spores with longitudinal ridges that measure 11–18 × 5–8 µm.

420 · Boletes of Eastern North America Genus Xerocomus Quél. The genus Xerocomus was erected in 1887 to accommodate small- to medium-size boletes formerly placed in the genus Boletus that have a dry cap and stalk and tubes that split lengthwise when torn, forming split half-tubes. The tubes of Boletus species remain intact when torn apart. Many species that were at one time placed in Xerocomus have been reclassified, leaving less than a dozen species that occur in eastern North America. They have soft flesh and caps that often become cracked. Microscopically, species of Xerocomus have long, smooth, nonencrusted cuticular cap hyphae; dense, parallel, nondivergent hyphal trama; and short to elongate, ellipsoidal to oblong, or subfusiform spores with a bacillate shape. The genus Xerocomellus is very similar to Xerocomus, but species in Xerocomellus have short, broad, and encrusted cuticular cap hyphae and longitudinally striate or smooth spores. A useful macroscopic feature for recognizing species of Xerocomus and Xerocomellus is the tendency of their tubes to split lengthwise when cut or torn owing to the parallel, nondivergent hyphal trama. The tubes of boletes in other genera remain intact when cut or torn because they have strongly divergent hyphal trama. There are no significant macroscopic characteristics that differentiate species of Xerocomus from species of Xerocomellus. Xerocomus hortonii (A)

Xerocomus · 421 Xerocomus hortonii (A. H. Sm. & Thiers) Manfr. Binder & Besl = Boletus hortonii A. H. Sm. & Thiers Common name(s): Corrugated Bolete, Horton’s Bolete Overview: The species name honors American mycologist Charles Horton Peck (1833–1917). The deeply pitted to corrugated cap, yellow pores, and smooth to lightly pruinose stalk are this unusual bolete’s distinctive features. The cap surface develops a blue-green flash and then stains olive brown with NH4OH. Cap: 4–10 cm wide, convex to broadly convex, margin even; surface dry to somewhat viscid, deeply pitted and corrugated, tan to reddish tan or ocher brown to reddish brown; flesh whitish to pale lemon yellow, unchanging when exposed; odor and taste not distinctive. Pores and tubes: yellow at first, becoming olive yellow with age, unchanging or rarely and slowly staining blue when bruised; tubes 5–10 mm deep. Stalk: enlarged downward or nearly equal, solid; surface dry, smooth to lightly pruinose or occasionally with delicate reticulation on the upper half, pale yellow to tan, sometimes reddish at the base; flesh concolorous with the cap flesh. Habitat and season: solitary, scattered, or in groups under broadleaf trees or in mixed woods, especially with oak, hickory, beech, and hemlock; late spring through fall. Xerocomus hortonii (B)

422 · Boletes of Eastern North America Distribution and frequency: eastern Canada south to Georgia, west to Minnesota and Arkansas; occasional to fairly common. Spore print: olive brown. Microscopic features: spores 12–15 × 3.5–4.5 µm, somewhat boat-shaped, smooth, yellow. Edibility: edible and very good. Lookalikes: Hemileccinum subglabripes (p. 220) is nearly identical. It differs by having a relatively smooth cap and a scurfier stalk. Leccinum rugosiceps (p. 262) has a pitted to cracked cap, flesh that stains dull reddish when cut, and brownish scabers on its stalk. Xerocomus hypoxanthus Singer = Boletus hypoxanthus (Singer) Murrill Common name(s): none. Overview: The term hypoxanthus means “yellow beneath,” referring to the color of this bolete’s pores and stalk. The cap surface stains blue to green blue with NH4OH or KOH. The flesh stains blue to bluish with NH4OH. Additional identification features include a brown cap that often becomes cracked with age and yellow flesh that sometimes stains blue when exposed. Xerocomus hypoxanthus

Xerocomus · 423 Cap: 2.5–7 cm wide, convex, becoming broadly convex to nearly plane, margin even or nearly so; surface dry, somewhat velvety to granular, often finely cracked in age, tawny brown to pale red brown or pale yellow brown to orange brown; flesh yellowish to yellow, staining slightly blue or not at all when exposed; odor and taste not distinctive. Pores and tubes: yellow, staining bluish or greenish when bruised or sometimes unchanging, often depressed at the stalk in age; pores usually elongated near the stalk; tubes 6–12 mm deep. Stalk: nearly equal, solid; surface dry, pale yellow to pale tawny with a yellow apex and often with a yellow base, usually coated with tiny brownish powdery flakes over the midportion, basal mycelium yellow; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary, scattered, or in groups on sandy soil or humus in broadleaf woods, especially with oak, in mixed oak and pine woods, or on decaying trunks of broadleaf trees or saw palmetto; summer and fall. Distribution and frequency: South Carolina and Florida, west along the Gulf Coast to Mississippi, distribution limits yet to be established; occasional. Spore print: olive brown. Microscopic features: 8–14 × 4–5 µm, fusoid, smooth, yellowish. Edibility: unknown. Lookalikes: Xerocomus hemixanthus (Singer) Murrill (not illustrated) is similar but has a dark-brown to reddish-brown or chestnut-brown cap, reddish-brown raised ribs near the stalk apex, and a white to yellowish-white basal mycelium. Its cap surface stains dark reddish brown with KOH and tan with NH4OH. Boletus ochraceoluteus (p. 125) has flesh that stains reddish and then bluish green and a cap surface that stains reddish brown with KOH or NH4OH. Xerocomus pseudoboletinus (Murrill) Singer (not illustrated) occurs from Florida west to Texas, has a large (up to 18 cm wide), reddish-brown to ochraceous-tawny cracked cap, with yellow showing in the cracks of mature specimens, and yellow flesh that is unchanging or sometimes staining weakly green when exposed. The pores are yellow and stain blue when bruised. The pores are elongated near the stalk, which is pale yellow on the upper portion and brownish toward the base, with coarse, brownish longitudinal ribs.

Xerocomus illudens / tenax complex (A) Xerocomus illudens / tenax complex (B)

Xerocomus illudens / tenax complex (C) Xerocomus illudens / tenax complex (D)

426 · Boletes of Eastern North America Xerocomus illudens (Peck) Singer / Xerocomus tenax (A. H. Sm. & Thiers) Halling & Nuhn complex Common name(s): none. Overview: In 1898, Charles H. Peck (1833–1917) described Boletus illudens. When Alexander Smith and Harry Thiers examined Peck’s type collection, they discovered that it was a mixture of two species, and they designated a lectotype for Boletus illudens Peck that represented Peck’s original description of it. In 1971, they described Boletus tenax, which is currently considered an illegitimate name, having been previously assigned to a different species in 1777. Smith and Thiers described the stalk of Boletus tenax as having a distinct, wide-meshed, fine reticulum overall or only over the upper half. In addition, they wrote in their description of Boletus illudens that its stalk was usually marked by coarse ridges and anastomosing lines but was not finely reticulate. The descriptions of Boletus illudens by other mycologists, including Ernst E. Both, William Coker and Alma Beers, Rolf Singer, and Walter Snell and Esther Dick, report its stalk to be strongly reticulated. For many years, mycologists have struggled with this conflicting information and the problem of how to differentiate Xerocomus illudens from Boletus tenax. Some authors have attempted to use macroscopic or microscopic features or macrochemical testing, but the results have always been inconclusive owing to taxonomic uncertainty of the specimens tested or examined. Recent phylogenetic analysis places Boletus tenax in the Xerocomus clade, therefore supporting the new combination Xerocomus tenax Nuhn & Halling (2015). It is possible that Xerocomus illudens and X. tenax are the same species or that two or more species are collectively represented by these two taxa. Until additional molecular analysis has been done, we have elected to consider the two a species complex. The term illudens means “to deceive,” a reference to this bolete’s similarity with other species. The term tenax means “tenacious, tough, or firm,” in reference to the texture of its stalk or its tenacious hold on the substrate. Cap: 3–10 cm wide, convex, becoming nearly plane, sometimes slightly depressed, margin even, incurved at first, sometimes uplifted, lobed, and irregular at maturity; surface dry, somewhat velvety, yellow brown to pinkish cinnamon or dull brick red to reddish brown, sometimes with an olivaceous tint; flesh whitish to pale yellow, unchanging or slowly staining pinkish red when exposed; odor not distinctive; taste acidic or not distinctive. Pores and tubes: bright yellow at first, becoming dingy yellow and depressed at the stalk when mature, usually slowly staining cinnamon red or sometimes slowly staining bluish and then cinnamon red, rarely unchanging

Xerocomus · 427 when bruised; pores large, angular to somewhat rounded, larger near the stalk; tubes 8–16 mm deep. Stalk: tapered downward or sometimes nearly equal, solid, firm or sometimes almost woody at the base; surface dry, reticulate overall or at least on the upper portion or with raised longitudinal lines that may form a partial reticulum at the apex or nearly overall, whitish with pale-rose to pinkish-cinnamon or yellowish tints; flesh concolorous with the cap flesh. Habitat and season: solitary, scattered, or in groups in broadleaf woods with oak or under pines; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; occasional. Spore print: olive brown. Microscopic features: spores 9–14 × 4–6 µm, ellipsoidal to subfusoid, smooth, dull yellow to pale brown. Edibility: unknown. Lookalikes: none. Xerocomus morrisii

428 · Boletes of Eastern North America Xerocomus morrisii (Peck) M. Zang = Boletus morrisii Peck Common name(s): Red-speckled Bolete Overview: This species was named for Boston mycologist and artist George Edward Morris (1853–1916), the collector of the type specimen. The red-dotted stalk ornamentation on this unusual and distinctive bolete is similar to scabers on the stalks of species in the genus Leccinum, which are brown or black. Cap: 3–9 cm wide, convex to broadly convex with a narrow, overlapping band of sterile tissue at the margin; surface dry, somewhat velvety at first and becoming glabrous in age, olive brown to reddish brown, often yellow to olive gold on the margin; flesh pale yellow, slowly staining reddish when exposed; odor and taste not distinctive. Pores and tubes: yellow to orange yellow or tinged reddish near the stalk, becoming orange to brownish orange in age, deeply depressed at the stalk of mature specimens, partial veil absent; tubes 6–12 mm deep. Stalk: nearly equal or enlarged downward, solid; surface yellow beneath a covering of reddish or reddish-brown punctae, basal mycelium yellow; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary or sometimes in small groups, with pine, often in sandy soil; summer and fall. Distribution and frequency: New England south to Georgia, west to Tennessee; generally uncommon to rare but may be somewhat common locally. Spore print: olive brown Microscopic features: spores 10–16 × 4–6 µm, ellipsoidal to spindle-shaped, smooth, yellowish. Edibility: reported to be edible but has an unpleasant taste. Lookalikes: Leccinum rubropunctum (p. 261) is similar, but its yellowish flesh does not stain when exposed, and it has an unpleasant odor reminiscent of stale cigarette butts in an ashtray. Its pores become dull yellow in age.

Xerocomus sclerotiorum (A)