Boletes of Eastern North America

280 · Boletes of Eastern North America Pores and tubes: bright yellow at first, becoming greenish yellow and then brownish yellow in age, quickly staining blue and then slowly becoming brownish when bruised, depressed at the stalk at maturity; tubes 8–12 mm deep. Stalk: up to 5 cm thick, enlarged downward, solid; surface dry, bright yellow to yellow, quickly staining blue and then slowly brownish when bruised, sometimes with reddish tints, especially near the base, typically lacking reticulation but sometimes reticulate on the upper portion; flesh yellow on the upper portion, dark red at the base, quickly staining blue at the base or overall when exposed. Habitat and season: solitary, scattered, or in groups under broadleaf trees, especially oak, or in mixed oak and pine woods, sometimes under pines; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; occasional to locally fairly common. Spore print: olive brown. Microscopic features: spores 10–16 × 4–6 µm, fusoid to ellipsoid-fusoid, smooth, brownish yellow. Edibility: edible. Lookalikes: The mature cap of Alessioporus rubriflavus (p. 56) has streaks and splashes of various shades of wine red, red brown, and ocher over a yellow ground color and becomes olive to brownish over the disc in age, but the cap of young specimens is wine red. Its stalk is distinctly reticulated, at least over the upper half. Compare with Lanmaoa carminipes (p. 231). Genus Par agyrodon Singer The genus Paragyrodon was erected in 1942 to accommodate a single species formerly classified in several genera, including Boletus, Gyrodon, and Suillus. This bolete has an unusual combination of characters: a thick double veil, decurrent pores, subglobose spores, and an association with oak. The spore-print color is dark yellow brown to olive brown. The name Paragyrodon means “close to Gyrodon,” a genus in which the Ash Tree Bolete, Boletinellus merulioides (p. 82), was formerly classified.

Paragyrodon sphaerosporus (A) Paragyrodon sphaerosporus (B)

282 · Boletes of Eastern North America Paragyrodon sphaerosporus (Peck) Singer = Boletus sphaerosporus Peck = Gyrodon sphaerosporus (Peck) Singer = Suillus sphaerosporus (Peck) A. H. Sm. & Thiers Common name(s): Double-veiled Bolete Overview: The term sphaerosporus means “rounded spores.” According to Michael Kuo and Andrew Methven (2014), dried specimens yielded the following reactions: the cap surface stains red to pinkish with KOH and grayish with FeSO4 and is negative with NH4OH; the flesh stains red to pinkish with KOH and grayish with FeSO4 and is negative with NH4OH. The presence of a veil excludes this mushroom from the genus Boletus. The combination of subglobose spores and hymenial cystidia separates it from Suillus species, which have ellipsoidal to fusiform spores and typically have resinous dots and smears containing cystidia in bundles on the stalk. Cap: 4–18 cm wide, convex, becoming broadly convex to nearly plane, sometimes shallowly depressed in age, margin incurved at first, becoming decurved to uplifted and irregular, and fringed with remnants of the partial veil; surface viscid to glutinous, glabrous, buff yellow to golden yellow or ocher, becoming dingy yellow brown to reddish brown in age, staining brown when bruised; flesh whitish to yellowish, staining vinaceous brown when exposed; odor and taste not distinctive. Pores and tubes: yellow, becoming brownish in age, staining tawny to cinnamon when bruised, attached to subdecurrent, covered by a partial veil when young; tubes 4–10 mm deep. Stalk: nearly equal, solid; surface dry, yellow above the ring, white to yellowish below, staining brownish when bruised; partial veil whitish, sheathing the entire stalk and attached to the cap margin, tough, fibrous-membranous with an inner gelatinous layer, tearing to form a median ring on the stalk and leaving remnants on the cap margin; ring double, fibrous-membranous on the outside, gelatinous on the inside; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary or in groups under broadleaf trees, especially oak, and sometimes found in suburban areas beneath shade trees; summer and fall. Distribution and frequency: eastern Canada, Michigan, Minnesota, and Wisconsin; infrequent. Spore print: dark yellow brown to olive brown. Microscopic features: spores 6–9 × 6–8 µm, globose to subglobose, smooth, ochraceous to brownish. Edibility: unknown. Lookalikes: none.

Phylloporus · 283 Genus Ph ylloporus Quél. The genus Phylloporus was erected in 1888 to accommodate species formerly classified in several genera, including Agaricus, Boletus, and Gomphidius. The name Phylloporus means “leaf pores,” a reference to the gill-like fertile surface. Phylloporus is a small, mostly tropical genus, with only three species known from eastern North America. Species in this genus are small to medium terrestrial boletes with a typically decurrent gill-like to poroid spore-bearing layer. They have dry caps with white to yellowish flesh, which in most species does not stain blue when exposed. Spore-print colors are yellowish ochraceous to olive brown. Phylloporus boletinoides (A)

Phylloporus boletinoides (B) Phylloporus leucomycelinus (A)

Phylloporus · 285 Phylloporus boletinoides A. H. Sm. & Thiers Common name(s): none. Overview: The term boletinoides means “having radially arranged and elongated pores.” The cap surface stains reddish to red brown with NH4OH and is negative with FeSO4. Cap: 2–10 cm wide, broadly convex when young, becoming nearly plane and sometimes shallowly depressed in age, margin strongly incurved when young and remaining so at maturity, with a narrow band of sterile tissue; surface dry, somewhat velvety to minutely scaly, becoming nearly smooth at maturity, cinnamon to dark pinkish brown, fading to dull yellow brown in age; flesh white to whitish, slowly staining bluish gray to gray when exposed; odor not distinctive; taste not distinctive or slightly acidic. Pores and tubes: gill-like with numerous crossveins or poroid, radially arranged and strongly decurrent; pale olive buff when young, becoming dark olive buff at maturity, at times with a bluish-green tinge near the margin in age, usually unchanging but sometimes slowly staining bluish green to dark blue when bruised; tubes 3–5 mm deep. Stalk: tapered downward to nearly equal, solid or hollow in the base; surface dry, smooth, pale yellow at the apex, pale cinnamon below, with a sparse layer of white basal mycelium; flesh colored like the cap flesh or darker cinnamon toward the base. Habitat and season: solitary or scattered in mixed pine and oak woods; summer, fall, and early winter. Distribution and frequency: Maine south to Florida, west to Texas; infrequent to fairly common, especially in the southern part of its range. Spore print: olive brown. Phylloporus leucomycelinus (B)

286 · Boletes of Eastern North America Microscopic features: spores 11–16 × 5–6.5 µm, subcylindrical to narrowly oval, smooth, pale brown. Edibility: unknown. Lookalikes: Phylloporus leucomycelinus (see photos, p. 284) and Phylloporus rhodoxanthus (p. 286) are similar but have redder caps and yellow to golden-yellow gill-like pores. Phylloporus rhodoxanthus (Schwein.) Bres. = Phylloporus foliiporus (Murrill) Singer = Phylloporus rhodoxanthus ssp. foliiporus (Murrill) Singer = Xerocomus rhodoxanthus (Schwein.) Bres. & Manfr. Binder Common name(s): Gilled Bolete Overview: This mushroom has the general aspect of a bolete from above and of a gilled mushroom from below. The term rhodoxanthus means “rose yellow.” The cap surface stains blue with NH4OH. Phylloporus foliiporus was once thought to be a distinct species because its pores stain greenish blue when cut or bruised. Cap: 4–10 cm wide, convex, becoming broadly convex to nearly plane or shallowly depressed in age, margin incurved at first; surface dry, somewhat velvety, often cracked, with yellowish flesh showing in the cracks, dull red to reddish brown, reddish yellow, or olive brown; flesh thick near the center, pale yellow; odor and taste not distinctive. Pores and tubes: strongly decurrent, deep yellow to olivaceous yellow, infrequently staining bluish when bruised; fertile portion 8–16 mm deep, occasionally somewhat poroid but typically gill-like with crossveins, radially Phylloporus rhodoxanthus

Pseudoboletus · 287 arranged, often wrinkled and sometimes forked, not easily separable from the cap. Stalk: usually tapered downward, with a swollen base or sometimes nearly equal, firm, solid; surface dry, scurfy or punctate with small reddish-brown dots and points, usually with lines extending down from the gill-like pores, yellow with reddish tinges, with yellow basal mycelium; flesh concolorous with the cap flesh. Habitat and season: solitary, scattered, or in groups in broadleaf woods, especially with oak or beech, sometimes in conifer woods; summer and fall. Distribution and frequency: throughout eastern North America; occasional to fairly common. Spore print: olivaceous yellow brown. Microscopic features: spores 8–14 × 3–5 µm, ellipsoid to fusoid, smooth, pale yellowish. Edibility: edible and usually good, although some collections have a bitter component that makes them unpalatable. Lookalikes: Phylloporus leucomycelinus (see photos, p. 284) is nearly identical but has white basal mycelium. Its pores sometimes stain bluish when cut or bruised. Genus Pseudobolet us Šutara The genus Pseudoboletus was erected in 1991 to accommodate a single species formerly classified in several genera, including Boletus, Suillus, and Xerocomus. This unique bolete, Pseudoboletus parasiticus, only grows attached to the earthball, Scleroderma citrinum. It has a dry and shiny cap and a dry, smooth stalk. It is the only species in this genus that occurs in eastern North America. Pseudoboletus parasiticus

288 · Boletes of Eastern North America Pseudoboletus parasiticus (Bull.) Šutara = Boletus parasiticus Bull. = Xerocomus parasiticus (Bull.) Quél. Common name(s): Parasitic Bolete Overview: The term Parasiticus means “parasitic,” a reference to the relationship this bolete has with its mycorrhizal associate. This unusual bolete is easy to identify because of its specific association with the earthball Scleroderma citrinum. It is interesting that the Parasitic Bolete is apparently edible, but its earthball host is poisonous. Cap: 2.5–6.5 cm wide, rounded to convex, margin incurved when young; surface dry, somewhat velvety, becoming glabrous and shiny in age, ocher brown to tawny olive or like tarnished brass; flesh pale yellow, unchanging when exposed; odor and taste not distinctive. Pores and tubes: yellow, becoming olivaceous with age, sometimes with reddish or rusty stains, unchanging or very rarely slightly bluish when bruised, often somewhat decurrent; tubes 3–6 mm deep. Stalk: nearly equal, usually curved, solid; surface dry, matted- fibrillose, concolorous with the cap, with white to very pale-yellow mycelium at the base; flesh concolorous with the cap flesh. Habitat and season: solitary, in small groups or clusters attached at the base of Scleroderma citrinum, parasitic; summer and fall. Distribution and frequency: eastern Canada south to Georgia, west to Mississippi and Minnesota; occasional to fairly common. Spore print: olive brown. Microscopic features: spores 12–18.5 × 3.5–5 µm, ellipsoidal, smooth, pale brown. Edibility: edible or at least nonpoisonous. Lookalikes: none. Genus Pulv erobolet us Murrill The genus Pulveroboletus was erected in 1909 to accommodate species formerly classified in several genera, including Boletus, Ceriomyces, and Suillus. At present, only four species are known to occur in eastern North America. Although united by DNA analysis, this odd assemblage of species has a variety of macroscopic features that are erratically expressed. Most of the species in this genus have a dry, often powdery, coated cap, but one has a viscid to glutinous cap. They have white to pale-yellow flesh that slowly stains blue in one of the four species and produce an olive-brown to ocher-brown or grayish-brown spore print.

Pulveroboletus · 289 Pulveroboletus atkinsonianus (Murrill) L. D. Gomez = Boletus atkinsonianus (Murrill) Sacc. & Trotter = Ceriomyces atkinsonianus Murrill Common name(s): none. Overview: This bolete was named in honor of American mycologist George F. Atkinson (1854–1918). The reddish-brown to reddish-cinnamon cap with a sterile margin, pale-yellow pores, and cartilaginous stalk that is enlarged downward are distinctive features. Pulveroboletus atkinsonianus

290 · Boletes of Eastern North America Cap: 9–14 cm wide, convex, becoming broadly convex at maturity, margin inrolled when young, with a thin band of sterile tissue; surface dry, viscid when wet, smooth, glabrous, sometimes becoming cracked at maturity, reddish brown to reddish cinnamon, becoming much darker brown in age, often with a pinkish tinge; flesh white, becoming pale pinkish red and sometimes staining blue when exposed; odor not distinctive; taste sweet or not distinctive. Pores and tubes: pale yellow at first, becoming olivaceous brown at maturity, sometimes slightly depressed at the stalk in age, unchanging when bruised; tubes up to 1 cm deep. Stalk: enlarged downward to somewhat bulbous at the base, solid, cartilaginous; surface dry, becoming viscid when wet, glabrous, often longitudinally ridged, concolorous with the cap but paler, pale yellow at the apex, sometimes staining reddish; flesh white, unchanging when exposed. Habitat and season: solitary, scattered, or in groups in broadleaf or mixed woods usually associated with oak or hemlock; summer. Distribution and frequency: reported from Georgia, New York, North Carolina, and West Virginia, distribution limits yet to be established; uncommon. Spore print: dark olivaceous to dull brownish. Microscopic features: spores 11–13 × 4–5 µm, fusiform, smooth, yellowish. Edibility: unknown. Lookalikes: Boletus nobilissimus (p. 123) has a similarly colored cap with a distinct sterile incurved margin. However, its cap is strongly pitted to corrugated or rarely only slightly pitted, and it has a reticulate stalk. Pulveroboletus auriflammeus (A)

Pulveroboletus · 291 Pulveroboletus auriflammeus (Berk. and M. A. Curtis) Singer = Boletus auriflammeus Berk. & M. A. Curtis Common name(s): Flaming Gold Bolete Overview: The term auriflammeus means “flaming gold,” a reference to the overall colors of this bolete’s fruitbody. This small- to medium-size bolete is striking for its overall deep, rich yellow-orange color. Handling this beautiful bolete will stain fingers yellow. The cap surface shows a faint blue flash and then stains vinaceous brown or darker orange with NH4OH, stains dull brown or dark amber after the yellow is dissolved with KOH, and is negative with FeSO4. Cap: 4–9 cm wide, convex to broadly convex, becoming nearly plane in age, margin even; surface velvety to powdery at first, sometimes finely cracked, bright orange yellow to golden yellow or brownish orange; flesh white to cream or pale yellow, not staining blue and not darkening when exposed; odor not distinctive; taste somewhat acidic or not distinctive. Pores and tubes: yellow to yellow orange, sometimes tinged with red, not staining blue when bruised, radially elongated and often depressed at the stalk at maturity; tubes 6–15 mm deep. Stalk: nearly equal, tapered in either direction or sometimes clavate with a pinched base, solid; surface dry, somewhat powdery at first, concolorous Pulveroboletus auriflammeus (B)

292 · Boletes of Eastern North America with the cap or more intensely yellow orange, coarsely reticulate overall or at least on the upper portion of mature specimens, reticulation often absent or indistinct on young specimens but possibly having longitudinal ribs, with white basal mycelium; flesh concolorous with the cap flesh. Habitat and season: solitary or in small groups or caespitose clusters in broadleaf or mixed woods, especially with oak; summer and fall. Distribution and frequency: New York south to Florida, west to Ohio and Tennessee; occasional. Spore print: olive brown to ocher brown. Microscopic features: spores 8–12 × 3–5 µm, subellipsoid to subfusiform, smooth, nearly hyaline. Edibility: unknown. Lookalikes: Boletus aurantiosplendens (p. 90) is similar but has an orange to brownish-orange or brownish-yellow cap, a yellow to apricot or orange stalk with tawny to reddish-brown streaks that do not stain fingers when handled, and brighter-yellow pores that do not develop crimson tints. Retiboletus ornatipes (p. 300) is a somewhat similar but more robust bolete with coarse, raised reticulation on the stalk and variable cap colors that range from yellow to olive, brown, or gray. Pulveroboletus curtisii (A)

Pulveroboletus curtisii (B) Pulveroboletus curtisii (C)

294 · Boletes of Eastern North America Pulveroboletus curtisii (Berk.) Singer = Boletus curtisii Berk. Common name(s): none. Overview: Other than from a few locations, this small, relatively uncommon bolete is not well known. It was named in honor of the nineteenth-century American clergyman turned mycologist Moses Ashley Curtis (1808–1872). This brightly colored bolete bears a superficial resemblance to the genus Suillus, but it lacks the resinous dots on the stalk that characterize many in that genus. The gluten on its cap has an acidic taste and stains fingers yellow. Cap: 3–9.5 cm wide, obtuse to convex, becoming broadly convex to nearly plane in age, margin with a narrow band of sterile tissue, incurved when young; surface bright yellow to orange yellow, initially dusted with an orange powdery coating, viscid and glutinous when fresh, becoming glabrous as the orange coating disappears, sometimes with brownish tints or whitish areas in age; flesh whitish, unchanging when exposed; odor and taste not distinctive. Pores and tubes: whitish to buff, pale yellow, or bright yellow orange at first, duller and brownish at maturity, unchanging when bruised, often depressed at the stalk in age; tubes 6–12 mm deep. Stalk: nearly equal, solid or hollow; surface viscid to glutinous when fresh, somewhat scurfy near the apex, nearly smooth below, pale yellow to yellow down to a base sheathed with cottony white mycelium; flesh concolorous with the cap flesh. Habitat and season: solitary, scattered, or in groups in conifer or mixed woods, often with pines; summer and fall. Distribution and frequency: New England south to Florida, west to Texas; occasional. Spore print: olive brown. Microscopic features: spores 9.5–17 × 4–6 µm, ellipsoidal to subventricose, smooth, yellowish. Edibility: unknown. Lookalikes: Boletus aureissimus var. aureissimus (p. 92) has a yellow cap, yellow unchanging flesh, yellow pores, and a yellow stalk that typically has delicate yellow reticulation on the upper portion.

Pulveroboletus · 295 Pulveroboletus ravenelii (Berk. & M. A. Curtis) Murrill = Boletus ravenelii Berk. & M. A. Curtis = Suillus ravenelii (Berk. & M. A. Curtis) Kuntze Common name(s): Ravenel’s Bolete, Powdery Sulphur Bolete Overview: The specific epithet honors American botanist-mycologist Henry William Ravenel (1814–1887). This bolete is easy to recognize when young by the floccose-powdery coating on the fruitbody and the delicate cottony ring that usually remains on the upper stalk, at least initially, after the partial veil ruptures. Cap: 2.5–10 cm wide, convex, becoming broadly convex to nearly plane, margin incurved at first, usually fringed with partial-veil remnants; surface dry and powdery to matted and tacky or glabrous when moist, bright yellow, soon becoming reddish orange to reddish brown on the disc; flesh thick, white to yellow, staining pale blue and then brownish when cut or injured; odor not distinctive or somewhat like hickory leaves; taste acidic. Pores and tubes: bright yellow becoming greenish yellow to greenish olive, bruising greenish blue, covered at first with a bright-yellow, cottony partial veil; tubes 5–8 mm deep. Stalk: nearly equal, solid; surface dry, floccose to fibrillose-matted from the base up to a delicate cottony ring near the apex, smooth above the ring, bright yellow; ring fragile, sometimes integrated with the floccose surface of the stalk and inconspicuous; flesh concolorous with and staining like the cap flesh. Pulveroboletus ravenelii

296 · Boletes of Eastern North America Habitat and season: solitary, scattered, or in groups in conifer woods, especially under pine or hemlock and rhododendron; summer and fall. Distribution and frequency: widely distributed from eastern Canada south to the Gulf of Mexico, west to Minnesota and Texas; occasional to fairly common locally. Spore print: olive brown to olive gray. Microscopic features: spores 8–10.5 × 4–5 µm, ellipsoidal to oval, smooth, pale brown. Edibility: edible. Lookalikes: Boletus melleoluteus (Snell, E. A. Dick & Hesler) T. J. Baroni & Halling (not illustrated) is a similar but uncommon bolete that has been recorded only from Georgia, North Carolina, and Tennessee. It grows in broadleaf woods, especially beneath oak. It has a smaller, bright-yellow to yellowish-olive or honey-yellow cap that does not develop reddish-orange to reddish-brownish tones at maturity, lacks a partial veil and ring, and has slightly longer spores, 7–12 × 3.5–4.5 µm. Genus Retibolet us Manfr. Binder & Bres. The genus Retiboletus was erected in 2002 to accommodate about a half-dozen boletes that produce unique pigment compounds called retipolides. The transfer of these species, which were formerly classified in the genus Boletus, is based on the combination of retipolide production, morphological characteristics, and molecular sequencing. Species in this genus have dry caps and prominently reticulate stalks. The spore-print colors are olive brown to dark yellow brown. Retiboletus griseus

Retiboletus · 297 Retiboletus griseus (Frost) Manfr. Binder & Bres. = Boletus griseus ssp. pinicaribaeae Singer = Boletus griseus var. griseus Frost = Xerocomus griseus (Frost) Singer Common name(s): Gray Bolete Overview: The term griseus means “grayish,” a reference to this bolete’s cap color. The key identification features include the grayish cap, unchanging whitish or slowly staining brownish flesh, whitish to brownish pores, and whitish to grayish stalk that develops yellow tones from the base upward as the bolete matures. Cap: 5–14 cm wide, convex, becoming broadly convex to nearly plane, sometimes slightly depressed, margin even; surface dry, appressed-fibrillose, fibrils grayish, often scaly in age, pale to dark gray or brownish gray when young, sometimes developing ocher tints in age; flesh whitish with dark yellow brown around larval tunnels, unchanging or slowly staining brownish when cut or bruised; odor and taste not distinctive. Pores and tubes: whitish to grayish or dingy gray brown, becoming pinkish brown in age, not yellow at any stage, unchanging or staining brownish or gray when bruised; tubes 8–20 mm deep. Retiboletus griseus var. fuscus

298 · Boletes of Eastern North America Stalk: nearly equal or tapered downward, often curved near the base, solid; surface whitish or grayish when young, developing yellow tones from the base upward with maturation, sometimes with reddish stains, covered overall with a coarse pale to yellowish reticulum that becomes brownish to blackish in age; flesh white with deep yellow at the base. Habitat and season: solitary or scattered in mixed broadleaf woods, especially under oak; summer and fall. Distribution and frequency: eastern North America west to Minnesota; occasional. Spore print: olive brown. Microscopic features: spores 9–13 × 3–5 µm, fusoid to oblong, smooth, pale brown. Edibility: edible and very good, although often damaged by insects; blemish-free specimens seldom found. Lookalikes: Retiboletus griseus var. fuscus (see photo, p. 297) is a variety of Retiboletus griseus that is known from Massachusetts, Florida, North Carolina, Virginia, and Japan. It has a darker-gray cap and whitish to yellowish flesh that slowly stains red when cut or bruised, grows under pines or in mixed pine and oak woods, and has larger spores, 11–17 × 4–6 µm. Retiboletus ornatipes (A)

Retiboletus ornatipes (B)

300 · Boletes of Eastern North America Retiboletus ornatipes (Peck) Manfr. Binder & Bres. = Boletus ornatipes Peck Common name(s): Ornate-stalked Bolete Overview: This common and attractive bolete with a strongly reticulate yellow stalk is easily recognized and always a pleasure to find. It seldom becomes damaged by insect larvae, but the flesh is too bitter to enjoy as an edible. The term ornatipes means “ornate foot,” a reference to this bolete’s coarsely reticulate stalk. The cap surface stains orangish to pale orange brown with KOH or NH4OH and is negative with FeSO4. Handling this showy bolete will stain fingers yellow. Cap: 4–20 cm wide, convex, becoming broadly convex to nearly plane or slightly depressed in the center in age; surface dull to somewhat powdery or slightly velvety, smooth, glabrous and shiny when dry, color variable from yellow, mustard yellow, and olive yellow to yellow brown or gray; flesh thick, yellow, unchanging when exposed; odor not distinctive; taste usually very bitter. Retiboletus ornatipes (C)

Rubroboletus · 301 Pores and tubes: bright lemon yellow to deep rich yellow, becoming dingy brownish yellow in age, staining yellow orange to orange brown when bruised; tubes 4–15 mm deep. Stalk: variable from nearly equal or swollen in the middle to tapered toward the base or less often with a swollen or club-shaped base, solid; surface dry, prominently and coarsely reticulate usually over the entire length, yellow to somewhat brownish, staining darker when bruised or handled; flesh concolorous with the cap flesh, rarely staining bluish at the base. Habitat and season: solitary or more often in groups, often in caespitose clusters in broadleaf or mixed woods, especially with oak or beech, sometimes under pine; late spring, summer, and fall. Distribution and frequency: widely distributed throughout eastern North America; common. Spore print: olive brown to dark yellow brown. Microscopic features: spores 9–13 × 3–4 µm, oblong to slightly ventricose with an obtuse apex, smooth, pale brown. Edibility: Some collections in the Northeast are mild tasting and edible, but the flesh of most collections is intensely bitter. Lookalikes: Gray-capped forms of Retiboletus ornatipes bear a strong resemblance to Retiboletus griseus (p. 297), which has mild-tasting flesh and is typically yellow only on the lower portion of the stalk. Both species often appear in the same habitat at the same time. Some authors recognize Retiboletus retipes (Berk. & M. A. Curtis) Manfr. Binder & Bres. (not illustrated) as a distinct species having a smaller cap, up to 5 cm in diameter; mild- to somewhat bitter-tasting flesh; and slightly larger spores, 11–15 × 3.2–4.2 µm. Boletus aureissimus var. aureissimus (p. 92) has a bright-yellow to honey-yellow or yellow-ocher cap, a yellow to bright-yellow stalk with or without delicate reticulation on the upper portion, and mild-tasting flesh. Also compare with Pulveroboletus auriflammeus (p. 291), which is similar but generally smaller and has a brownish-orange to golden-yellow or chrome-yellow cap and stalk. Genus Rubrobolet us Kuan Zhao & Zhu L. Yang The genus Rubroboletus was erected in 2014 to accommodate ten species distributed worldwide and by means of phylogenetic analysis shown to be related. The name Rubroboletus means “red bolete.” Species in this genus have a pinkish to reddish or sometimes grayish cap surface and orange-red to blood-red pores. They typically have yellow tubes, pink to red punctae or reticulation on the stalk, and a bluish color change when injured. To date, only two species have been reported from eastern North America.

302 · Boletes of Eastern North America Rubroboletus dupainii (Boud.) Kuan Zhao & Zhu L. Yang = Boletus dupainii Boud. = Suillellus dupainii (Boud.) Blanco-Dios Common name(s): none. Overview: The combination of reddish pores and a slimy-viscid cap is most unusual. Rubroboletus dupainii was described in 1902 from central France. The first specimens of this bolete recorded from outside of Europe were based on collections made by American mycologist Owen McConnell in North Carolina. Cap: 2.5–11 cm wide, rounded at first, becoming convex and finally broadly convex to nearly plane in age, margin incurved at first, becoming decurved and extending as a thin band of sterile tissue on mature specimens; surface smooth, slimy-viscid when fresh, becoming shiny when dry, purplish red to pinkish red or bright red, sometimes with yellowish spots; flesh whitish to pale yellow, quickly staining blue and then blackish blue when exposed; odor pleasant and musky or not distinctive; taste not distinctive. Pores and tubes: dark red at first, becoming carmine red to orange red and finally fading to yellow toward the margin in age, staining blue when bruised; tubes 4–10 mm deep, yellow to greenish yellow, bruising blue to greenish blue. Rubroboletus dupainii

Rubroboletus · 303 Stalk: enlarged downward and typically clavate with a somewhat pointed base or nearly equal, solid; surface dry, coated with fine reddish punctae that are more abundant toward the base, ground color yellow, typically with white basal mycelium, staining blue when bruised; flesh yellowish, becoming reddish toward the base, staining blue when exposed. Habitat and season: solitary, scattered, or in groups under broadleaf trees, especially oak and hickory, and in mixed woods; summer and early fall. Distribution and frequency: reported from North Carolina and Iowa; rare. Spore print: olive brown. Microscopic features: spores 10–17 × 3.5–6 µm, fusiform-ellipsoid to ellipsoidal, with prominent oil drops, smooth, light yellow. Edibility: unknown. Lookalikes: Boletus carminiporus (p. 97) is similar, but its cap is dry to subviscid; its flesh does not stain blue when exposed; and it has a distinctly reticulate stalk. Rubroboletus rhodosanguineus (A)

304 · Boletes of Eastern North America Rubroboletus rhodosanguineus (Both) Kuan Zhao & Zhu L. Yang = Boletus rhodosanguineus Both Common name(s): none. Overview: The term rhodosanguineus means “red to purplish-red blood,” a reference to this beautiful bolete’s red pores and stalk reticulation. Pink areas of the cap surface produce a bluish-slate flash with NH4OH. Cap: 6.5–14 cm wide, strongly rounded at first, becoming broadly convex to nearly plane in age, margin strongly incurved at first, becoming decurved, with a narrow band of sterile tissue; surface dry, somewhat velvety to nearly glabrous, becoming cracked in age, at first dark reddish pink to purplish pink or brick red with a silvery-white bloom, usually developing brown to olive tones, staining dark red to dark purplish (most noticeable on young specimens) and eventually gray when bruised; flesh yellow, instantly staining blue and then fading to dull grayish blue when exposed; odor of overripe fruit, perfume-like on drying; taste sweet to nauseatingly sweet. Pores and tubes: typically bright blood red to dark red or garnet red to moderate reddish brown at first, becoming dull orange red to dull coral red Rubroboletus rhodosanguineus (B)

Strobilomyces · 305 with yellowish-olive tints, sometimes yellow at first when very young, margin with a conspicuous golden-yellow zone, slightly depressed with a short decurrent tooth in age; tubes 7–14 mm deep, yellow to brownish olive, rapidly staining blue when cut. Stalk: strongly club-shaped to somewhat bulbous, solid; surface dry, golden yellow near the apex, pale yellow to pinkish below, typically red on the lower portion and white at the very base, sometimes with brownish spots and streaks, covered nearly overall by a delicate blood-red reticulum, staining blue to greenish on the red areas when bruised; flesh yellow with burgundy-red and golden-yellow areas in the base. Habitat and season: scattered or in groups, sometimes fused in clusters, under red oak; summer and fall. Distribution and frequency: known from eastern Canada, western New York, Ohio, and West Virginia, distribution limits yet to be established; rare to occasional. Spore print: olive brown. Microscopic features: spores 11–15 × 4.5–5.5 µm, subfusiform, smooth, pale yellow in water, yellow to pale amber in Melzer’s. Edibility: unknown. Lookalikes: Boletus flammans (p. 107) has a dark-red to brick-red, rosy-red, or brownish-red cap that lacks olive tones and does not stain dark red to purplish when bruised; the odor of its flesh is not distinctive; it has a less prominently reticulate stalk; and it grows under conifers. Genus St robilomyces Berk. The genus Strobilomyces was erected in 1851 to accommodate species formerly classified in the genus Boletus. The name Strobilomyces means “pinecone fungus,” a reference to the scales on the cap surface of boletes in this genus. Only three species of Strobilomyces are known to occur in eastern North America. They are easy to recognize as a group, although their macroscopic differences are subtle. In general, they are medium to large terrestrial boletes that have a dry, coarsely fibrillose to conspicuously scaly cap and a dry, woolly to shaggy stalk with a distinct ring zone. The pores, which are at first covered by a partial veil, are white but soon become gray and then black. These boletes have whitish flesh that quickly stains orange to orange red and then eventually blackish when exposed. Their spore-print color is brownish black to black.

Strobilomyces dryophilus Strobilomyces confusus

Strobilomyces · 307 Strobilomyces dryophilus Cibula & N. S. Weber Common name(s): none. Overview: The term dryophilus means “oak loving,” a reference to an association with oak trees. The cap surface stains brown with NH4OH or FeSO4 and dark reddish brown with KOH. The key identification features include the grayish-pink to pinkish-brown scales over a whitish ground color, whitish flesh that quickly stains orange to orange red and then slowly blackish, white pores that become black in age, and a pinkish-tan to brownish stalk that is ridged or reticulate above a ring and shaggy below. Cap: 3–12 cm wide, convex, becoming broadly convex to nearly plane in age, margin fringed with cottony pieces of a whitish to tan torn partial veil; surface dry, with a whitish ground color, covered with coarse, woolly or cottony, appressed or erect, grayish-pink to pinkish-tan or pinkish-brown scales; flesh whitish, quickly staining orange to orange red and then slowly blackish when cut or bruised; odor and taste not distinctive. Pores and tubes: white when young, soon becoming gray and eventually black, staining reddish orange or brick red and then black when bruised, covered by a whitish to pale pinkish-tan, cottony to woolly partial veil when young; tubes 1–1.7 cm deep. Stalk: nearly equal or sometimes enlarged at the base, solid, with a ring or shaggy zone; surface dry, pinkish tan to brownish, ridged or reticulate above the ring, shaggy to woolly below; flesh whitish, quickly staining orange to reddish orange and then slowly blackish when exposed. Habitat and season: solitary, scattered, or in groups under oaks or in mixed woods; summer, fall, and early winter. Distribution and frequency: Cape Cod, Massachusetts, south to Florida, west to Texas; occasional to frequent. Spore print: blackish brown to black. Microscopic features: spores 9–12 × 7–9 µm, subglobose to short-ellipsoidal, covered by a distinct and complete reticulum, grayish. Edibility: edible. Lookalikes: Strobilomyces strobilaceus (p. 309) is very similar, but it has a darker purplish-gray to blackish cap and stalk. Strobilomyces confusus (see photo, p. 306) is also similar, but it has a darker purplish-gray to blackish cap with smaller; more erect, stiff, and pointed scales; a darker stalk; and spores with irregular projections and short ridges that lack reticulation.

Strobilomyces strobilaceus (A) Strobilomyces strobilaceus (B)

Suillellus · 309 Strobilomyces strobilaceus (Scop.) Berk. = Strobilomyces floccopus (Vahl) P. Karst. Common name(s): Old Man of the Woods, Pine Cone Bolete Overview: The term strobilaceus means “like a pine cone,” a reference to this bolete’s overlapping cap scales. The cap surface stains brown with NH4OH or FeSO4 and dark reddish brown with KOH. The gray to purplish-gray or blackish scales, whitish flesh that quickly stains orange to orange red and then black, white pores that become black in age, and distinct annular zone on the stalk are the distinctive features. Cap: 3–15.5 cm wide, convex, becoming broadly convex to nearly plane in age, margin fringed with cottony pieces of grayish partial veil; surface dry, with a whitish to grayish ground color, covered with coarse woolly or cottony, flattened or erect, sometimes overlapping, gray to purplish-gray or blackish scales; flesh whitish, quickly staining orange to orange red and then black when cut or bruised; odor and taste not distinctive. Pores and tubes: white when young, soon gray, and then finally black in age, staining reddish to brownish or reddish brown and then black when bruised, covered by a cottony or woolly partial veil when young; tubes 1–1.5 cm deep. Stalk: nearly equal or sometimes enlarged at the base, solid, usually with a distinct shaggy annular zone; surface dry, grayish or concolorous with the cap, reticulate at the apex above the ring zone, shaggy to woolly below; flesh whitish, staining orange to reddish orange and then black when exposed. Habitat and season: solitary, scattered, or in groups under pines or oaks, sometimes with beech; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; fairly common. Spore print: blackish brown to black. Microscopic features: spores 9.5–15 × 8.5–12 µm, short-ellipsoidal to globose, covered by a distinct reticulum, grayish. Edibility: edible. Lookalikes: Strobilomyces confusus (see photo, p. 306) is nearly identical but has erect and pointier cap scales as well as spores with irregular projections and short ridges that sometimes resemble a partial reticulum. It also is widely distributed throughout eastern North America. Strobilomyces dryophilus (p. 307) has a dull grayish-pink to pinkish-tan cap that becomes darker brown in age, and its spores have a complete reticulum. Genus Suillellus Murrill The genus Suillellus was erected in 1909 to accommodate species formerly classified in the genera Boletus, Dictyopus, Leccinum, and Tubiporus. Currently, there are four known members of this genus from eastern North America. Species

310 · Boletes of Eastern North America in this genus are terrestrial, have a dry or slightly viscid cap that is glabrous or nearly so, a central stalk that is usually reticulate or pruinose to punctate, white to yellow flesh, and orange to red pores. The species that are currently included in this genus are closely related, as demonstrated by molecular analysis. Suillellus hypocarycinus (Singer) Murrill = Boletus hypocarycinus Singer Common name(s): none. Overview: The term hypocarycinus means “under hickory,” a reference to the type of trees in the habitat where this bolete grows. The yellow flesh that quickly stains blue when exposed, red to orange-red or dull-orange pores that quickly stain blue, and whitish to yellowish stalk with carmine-red punctae are its distinctive features. Cap: 4–12 cm wide, rounded to convex, becoming broadly convex in age, margin incurved when young, typically with a narrow band of sterile tissue; surface dry, somewhat velvety, brown to yellow brown, sometimes with olive or cinnamon tones; flesh yellow, quickly staining blue when exposed; odor and taste not distinctive. Pores and tubes: red to orange red or dull orange, quickly staining blue when bruised, usually somewhat depressed at the stalk at maturity; tubes 8–16 mm deep. Suillellus hypocarycinus

Suillellus · 311 Stalk: nearly equal or slightly enlarged downward, solid; surface dry, whitish to yellowish with a yellow apex, carmine-red punctae at least on the lower portion, with a white basal mycelium; flesh yellow, rapidly staining blue when exposed. Habitat and season: solitary, scattered, in groups on the ground or in decaying leaf litter under oak and hickory, especially in river bottomlands; summer and fall. Distribution and frequency: North Carolina south to Florida, west to Texas, distribution limits yet to be established; occasional. Spore print: olive brown. Microscopic features: spores 8–12 × 3–4 µm, subfusoid to ellipsoid, smooth, brownish yellow. Edibility: unknown. Lookalikes: Neoboletus luridiformis (p. 277) is very similar, but it has a more northern distribution, different macrochemical test reactions, and larger spores, 12–16 × 4.5–6 µm. Suillellus luridus (A)

312 · Boletes of Eastern North America Suillellus luridus (Schaeff.) Murrill = Boletus luridus Schaeff. Common name(s): Lurid Bolete Overview: The term luridus means “appearing dull dirty brown or smoky yellow,” a reference to the color of this bolete’s cap. The distinctive features include the variable yellowish to orange or brown cap, yellowish to reddish flesh that quickly stains blue, dark-red to orange-red or brownish-orange pores that instantly stain blackish blue when bruised, and yellow reticulate stalk with red tinges. Cap: 4–12.5 cm wide, convex, becoming broadly convex to nearly plane in age, margin with a narrow band of sterile tissue; surface dry, dull or shiny, somewhat velvety, color variable, yellowish to olive yellow, brownish orange, or olive brown, sometimes with pinkish or reddish tints, staining dark greenish blue to nearly blackish when bruised; flesh yellowish to reddish, sometimes with a red line above the tubes of freshly sectioned specimens, quickly staining blue when bruised; odor and taste not distinctive. Pores and tubes: dark red to orange red or brownish orange, instantly staining blackish blue when bruised, depressed at the stalk at maturity; tubes 1–2 cm deep. Suillellus luridus (B)

Suillellus · 313 Stalk: nearly equal or enlarged downward, solid; surface dry, pruinose to punctate, yellow on the upper portion with a red base or yellow streaked with red, sometimes red at the apex, with red to reddish-yellow reticulation nearly overall or at least on the upper portion; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary, scattered, or in groups in broadleaf or mixed woods or landscaped areas, usually with oak or hickory, sometimes under conifers; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; occasional. Spore print: olive brown. Microscopic features: spores 11–17 × 5–7 µm, ovoid to subellipsoid, smooth, yellow. Edibility: reportedly poisonous, causing gastrointestinal distress. Lookalikes: This bolete is sometimes confused with Suillellus subvelutipes (p. 315), which is similar but has an orange-brown cap, lacks reticulation on its stalk, and usually has short reddish or yellow hairs on its stalk base. Suillellus subluridus (p. 314) has a variably colored cap, yellow to orange with purple stains or entirely purplish red; yellow flesh that stains blue; and deep purple-red to dark-red pores that bruise blue. Its stalk is concolorous with the cap or yellow near the apex and red below, bruises blue, and lacks reticulation. Other similar species such as Suillellus hypocarycinus (p. 310) and Neoboletus luridiformis (p. 277) also lack reticulation on their stalks. Suillellus subluridus

314 · Boletes of Eastern North America Suillellus subluridus Murrill = Boletus miniato-olivaceus var. subluridus (Murrill) Singer = Boletus subluridus (Murrill) Murrill Common name(s): none. Overview: This southern bolete has not been recorded north of North Carolina. The term subluridus means “somewhat like Suillellus luridus” (p. 312), which is a typically drab-colored bolete. The key identification features include the variable orange-pink to orange-yellow or red to purplish-red cap, dark-red pores that stain blue, and the yellow stalk that is minutely punctate and reddish below. Cap: 4–11.5 cm wide, pulvinate to convex, becoming broadly convex to nearly plane in age, margin incurved at first, with a narrow band of sterile tissue when young, becoming even; surface dry, glabrous to velvety subtomentose, sometimes finely cracked in age, color variable, orange pink to orange yellow with vinaceous tints or red to purplish red, sometimes rusty red to cinnamon red, developing more brownish tones in age, staining dark blue when bruised; flesh pale yellow to yellow, staining blue when exposed, sometimes unchanging, especially in older specimens; odor weakly fetid or not distinctive; taste not distinctive. Pores and tubes: often partly yellow at first, especially near the margin, becoming purplish red to dark red overall and then fading to reddish orange to orange yellow in age, staining blue when bruised; tubes 6–12 mm deep. Stalk: tapered in either direction, sometimes ventricose, or nearly equal, with a pinched base, solid; surface dry, glabrous and yellow near the apex, minutely punctate and reddish below, often longitudinally striate, staining blue when bruised; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary, scattered, or in groups under broadleaf trees or in mixed woods, usually with oaks and pines; summer and fall. Distribution and frequency: North Carolina south to Florida, west to Mississippi, distribution limits yet to be established; uncommon. Spore print: olive brown. Microscopic features: spores 9–14 × 4–6 µm, fusoid to subfusoid, smooth, yellow. Edibility: unknown. Lookalikes: Similar species include Boletus flammans (p. 107), which has a reticulate stalk, and Boletus carminiporus (p. 97), which also has a reticulate stalk and flesh that does not stain blue when exposed.

Suillellus · 315 Suillellus subvelutipes (Peck) Murrill = Boletus subvelutipes Peck Common name(s): Red-mouth Bolete Overview: The term subvelutipes means “somewhat velvety foot,” a reference to the yellow or dark-red hairs often present on this bolete’s stalk base. Suillellus subvelutipes is one of the first boletes to appear in early spring, often under planted Norway spruce in lawns, parks, and cemeteries. All parts instantly stain dark blue to bluish black when handled. Cap: 6–13 cm wide, convex, becoming broadly convex to nearly plane in age, margin even; surface dry, somewhat velvety to nearly glabrous, occasionally cracked in age, color variable, cinnamon brown to yellow brown, reddish brown, or reddish orange to orange yellow, quickly staining dark bluish black when bruised; flesh bright yellow, quickly staining dark blue when exposed and then becoming whitish; odor not distinctive; taste slightly acidic or not distinctive. Pores and tubes: variable, red, brownish red, dark maroon red, or red orange to orange when fresh, often with a yellow rim, duller in age, quickly staining dark blue to blackish when bruised; tubes 8–26 mm deep. Suillellus subvelutipes

316 · Boletes of Eastern North America Stalk: nearly equal, solid; surface dry, scurfy, flushed red and yellow, typically yellow at the apex, quickly staining dark blue to blackish when handled, often with short, stiff, dark-red hairs at the base of mature specimens and yellow hairs on young specimens that become dark red with age; flesh concolorous with and staining like the cap flesh. Habitat and season: solitary, scattered, or in groups under broadleaf trees, especially oak, and sometimes under conifers, especially hemlock and Norway spruce; summer and fall. Distribution and frequency: widely distributed throughout eastern North America; fairly common. Spore print: dark olive brown. Microscopic features: spores 13–18 × 5–6.5 µm, fusoid-subventricose, smooth, pale brown. Edibility: traditionally considered to be poisonous. However, we have had several recent reports that some individuals have eaten this bolete without ill effects. We have not consumed it. Those who choose to experiment eating it should do so with great caution. Lookalikes: Neoboletus luridiformis (p. 277) has a dark-brown, velvety cap and lacks hairs on the base of its stalk. Boletus subluridellus (p. 163) has a bright-red to pinkish-red, orange-red, or brick-red cap and a yellow stalk with much less red, and the stalk base lacks yellow or dark-red hairs. Genus Suillus P. Micheli In 1729, Pier Antonio Micheli  (1679–1737) first erected the genus Suillus. Because this genus predated the accepted start date of Linnean taxonomy in 1753, it was not considered valid until 1821, when British botanist Samuel Frederick Gray (1766–1828) used it to describe a group of mushrooms in his work A Natural Arrangement of British Plants (1821). The name Suillus is derived from the Latin word sus, which means “small pig.” Suillus is a large genus that includes more than thirty species known from eastern North America. They are medium to large terrestrial boletes that almost exclusively grow in association with conifer trees and are often the last boletes to fruit in fall and early winter. Their caps may be dry to moist or viscid to glutinous. Spore prints are olive yellow, yellow brown, olive brown, cinnamon brown, or dark brown. These mushrooms have white or yellow or sometimes brown pores that may be rounded, angular, or elongated and radially arranged. The stalks are solid, and most are covered with conspicuous resinous dots or smears composed of bundles of pigmented caulocystidia. Some species have a partial veil that leaves a membranous or glutinous ring on the stalk. A very few species have reticulation on the stalk, especially above the ring. Scabers are lacking.

Suillus acidus (A) Suillus acidus (B)

318 · Boletes of Eastern North America Suillus acidus (Peck) Singer = Suillus acidus var. intermedius A. H. Sm. & Thiers = Suillus intermedius (A. H. Sm. & Thiers) A. H. Sm. & Thiers = Suillus subalutaceus (A. H. Sm. & Thiers) A. H. Sm. & Thiers Common name(s): Sour-cap Suillus Overview: The term acidus means “sour or acidic,” a reference to the taste of the gluten on this bolete’s cap. This small- to medium-size bolete is recognized by a persistent ring on the stalk and sour-tasting gluten on its cap cuticle. Cap: 5–16 cm wide, rounded to convex at first, becoming broadly convex to nearly plane in age, margin strongly incurved and remaining so well into maturity, often fringed with soft yellowish remnants of a partial veil; surface smooth, viscid when fresh, shiny when dry, coated with gluten that typically but not always has an acidic taste, yellowish when young, becoming tan, ocher yellow, or pinkish cinnamon to yellow brown and often streaked or spotted in age; flesh whitish to pale yellow or orange yellow, unchanging or slowly staining pale reddish brown when exposed; odor and taste not distinctive. Pores and tubes: pale yellow, with beads of fluid when fresh, dingy yellow in age, slowly staining pale reddish brown when bruised or sometimes unchanging, covered at first with a soft, cottony, yellow partial veil that is coated with gluten; tubes 4–10 mm deep. Stalk: nearly equal or enlarged downward, solid; surface pale yellow to ocher yellow, sometimes pinkish brown on the lower portion, with reddish to brownish resinous dots and smears that darken with age and a gelatinous band-like ring near the apex; flesh concolorous with and staining like the cap flesh. Habitat and season: scattered or in groups on the ground or among mosses under red or white pine; summer and fall. Distribution and frequency: eastern Canada south at least to North Carolina and Tennessee, west to Minnesota; occasional to fairly common. Spore print: tawny brown to dull cinnamon brown. Microscopic features: spores 8–11 × 3–5 µm, ellipsoidal to subfusoid, smooth, pale brown. Edibility: edible, with a lemony flavor. Lookalikes: Compare with Suillus hirtellus (p. 340), which lacks a ring. Also compare with Suillus tomentosus (p. 360), which lacks a ring and whose pore surface bruises blue.

Suillus · 319 Suillus americanus (Peck) Snell = Boletus americanus Peck = Boletus americanus var. americanus Peck = Boletus americanus var. reticulipes Coker & Beers = Suillus americanus var. reticulipes (Coker & Beers) Grand Common name(s): American Slippery Jack, Chicken-fat Suillus Overview: This bolete always occurs under white pine, with which it forms a host-specific mycorrhizal relationship. The term americanus means “of America.” The cap surface displays a pink flash and then stains red and finally black with NH4OH. The tissue that hangs from the cap margin of young specimens is not a remnant of a true partial veil because it is never attached to the stalk. When handled, this bolete stains fingers brownish. Although negative reactions are uncommon, some individuals develop contact dermatitis consisting of swelling and an itchy rash or develop irritation of the eyes if rubbed after this bolete is handled. The synonym Suillus americanus var. reticulipes, reported from North Carolina, was originally described as a distinct variety because it has coarse reticulation on its stalk and strongly decurrent pores. Cap: 3–13 cm wide, rounded with an incurved margin when young, becoming broadly convex in age, occasionally with an umbo, margin hung with white Suillus americanus

320 · Boletes of Eastern North America to yellow or pale-brown, cottony false-veil tissue; surface viscid to glutinous when moist, covered beneath the gluten by appressed fibrils and flattened scales, or sometimes nearly glabrous on young specimens, color bright yellow to ocher yellow with cinnamon to reddish patches or streaks; flesh yellow, staining pinkish gray to purplish brown when exposed; odor and taste not distinctive. Pores and tubes: yellow when young, slightly browner in age, slowly staining reddish brown when cut or bruised; pores angular, occasionally elongated and radially arranged, often somewhat decurrent; tubes 7–10 mm deep. Stalk: nearly equal, often crooked, solid at first, developing cavities or becoming hollow with age, not reticulate or rarely so at the apex, up to 10 mm thick, lacking a ring; surface dry, yellow, speckled with reddish to darkbrown resinous dots and smears, often developing wine-red or wine-brown stains when bruised or in age; flesh concolorous with and staining like the cap flesh. Habitat and season: sometimes solitary but usually in groups or caespitose clusters under white pine, often common in grassy areas in parks; summer and fall. Distribution and frequency: eastern Canada south to North Carolina and Tennessee, west to Minnesota; fairly common. Spore print: brown. Microscopic features: spores 8–11 × 3–4 µm, nearly fusiform, smooth, pale brown. Edibility: edible though not highly regarded. Lookalikes: Suillus subaureus (p. 358) is somewhat similar, but it lacks fragments of cottony veil tissue on its margin, grows in mixed woods with oak and pine, and occurs in broadleaf woods with oak where pine is absent. Suillus sibiricus (Singer) Singer (not illustrated), which is nearly identical, if not the same species, has been reported in eastern North America from Michigan and Ontario. It is described as having a thicker stalk, up to 15 mm wide, which is bright yellow and often reticulate at the apex. Its veil occasionally leaves a superior ring on the stalk but typically leaves only remnants on the cap margin. It also grows in association with pines.

Suillus · 321 Suillus bovinus (L.) Roussel = Boletus bovinus L. = Suillus bovinus var. viridocaerulescens (A. Pearson) Singer Common name(s): none. Overview: The term bovinus means “ox-like,” perhaps a reference to the color of this bolete’s cap. The cap surface and flesh stain vinaceous to burgundy with KOH or NH4OH and pale olive gray with FeSO4. This European bolete was likely introduced into North America with plantings of Scots pine. Cap: 3–10 cm wide, obtuse to convex at first, becoming broadly convex to nearly plane in age, margin incurved to inrolled at first; surface viscid, glabrous, ochraceous to rusty orange, sometimes with brownish tints, margin whitish; flesh pale yellow to saffron, at least in some areas slowly becoming dull orange pink when exposed, not staining blue when exposed; odor fruity and pleasant; taste somewhat sweet or not distinctive. Pores and tubes: grayish olive at first, becoming ochraceous to dull yellow and then dull olive brown, not staining when bruised, somewhat decurrent; pores angular, compound, highly variable, up to 2 mm wide on mature specimens; tubes 3–6 mm deep. Stalk: nearly equal, solid; surface dry, glabrous, dull yellow to ochraceous at first, developing reddish-brown stains in age or when handled, lacking Suillus bovinus

322 · Boletes of Eastern North America resinous dots and smears; flesh pale yellow and then dull ochraceous from the base upward in age, not staining when exposed. Habitat and season: solitary, scattered, or in groups among mosses and needle litter under Scots pine; late summer and fall. Distribution and frequency: Adirondack Mountains of New York, also reported from North Carolina, Pennsylvania, and Vermont; rare. Spore print: olive brown. Microscopic features: spores 8–10 × 3–4 µm, ellipsoid to subfusiform, smooth, hyaline to pale yellow in KOH, ochraceous in Melzer’s. Edibility: edible. Lookalikes: Suillus granulatus (p. 333) is similar, but its odor and the taste of its flesh are not distinctive; its stalk has conspicuous pinkish-tan to brownish resinous dots and smears; and it grows under white pine or very rarely with other pines, spruce, or hemlock. Suillus neoalbidipes (p. 344) is also similar. It has a paler cap with a wide band of whitish sterile tissue on the margin and a white stalk that at first lacks conspicuous resinous dots and smears but with age may exhibit some that become brownish. Suillus bresadolae var. flavogriseus

Suillus · 323 Suillus bresadolae var. flavogriseus Cazzoli & Consiglio = Suillus nueschii Singer Common name(s): Bearded Bolete Overview: This bolete has only recently been recorded from Newfoundland and is rare in eastern North America. The term bresadolae honors Italian mycologist Giacomo Bresadola (1847–1929). The term flavogriseus means “yellow and gray,” in reference to the colors of the pores. Cap: 2.5–10 cm wide, convex to broadly umbonate, margin incurved at first, becoming uplifted at maturity, with conspicuous floccose and white to yellow veil tissue especially on immature specimens; surface covered with yellow gluten, pale yellow to dull ocher with reddish-brown tones especially toward the margin, mottled and appearing scaly when drying; flesh whitish to pale yellow, staining slightly pinkish vinaceous when bruised; odor and taste not distinctive. Pore and tubes: whitish to very pale yellow at first, soon developing a grayish tint overall, becoming grayish brown at maturity, not staining when bruised, attached to slightly decurrent; pores angular to irregular. Stalk: nearly equal to slightly club-shaped, stout, solid; surface viscid, colored like the cap on the upper portion, darker reddish brown on the lower portion, sometimes with a deep-yellow base, with a superior to median, sheathing, whitish to yellow membranous ring, basal mycelium white or slightly pinkish; flesh pale yellowish green at first and then becoming olivaceous in age, staining like the cap flesh, especially near the base. Habitat and season: solitary, scattered, or in groups among mosses and needle litter under larch trees; fall. Distribution and frequency: in North America currently known only from Newfoundland; rare. Spore print: dull cinnamon. Microscopic features: spores 7.8–10.9 × 3–4.7 µm, subfusoid-ellipsoid, smooth, pale straw. Edibility: unknown. Lookalikes: Suillus grevillei (p. 335) is similar, but it has yellow pores and a much darker orange-yellow to reddish-brown cap. Suillus bresadolae var. bresadolae (Quél.) Gerhold, which has not been reported from North America, has a dark chestnut-brown cap.

Suillus brevipes (A) Suillus brevipes (B)

Suillus · 325 Suillus brevipes (Peck) Kuntze = Boletus brevipes Peck = Rostkovites brevipes (Peck) Murrill = Suillus brevipes var. subgracilis A. H. Sm. & Thiers = Suillus pseudogranulatus (Murrill) Murrill Common name(s): Short-stalked Suillus, Short-stemmed Slippery Jack Overview: This bolete is aptly named. The term brevipes means “short foot,” a reference to its typically short stalk, which is often so short that the cap appears to rest directly on the ground. The resinous dots exhibited on the stalk of most members of the genus Suillus are absent or colorless and inconspicuous (use hand lens) on this species. Cap: 4–10 cm wide, hemispheric to obtuse at first, becoming broadly convex to nearly plane in age, margin incurved at first, even; surface viscid to glutinous, smooth and glabrous, usually with adhering pine needles and debris, light brown to dark brown, vinaceous brown to cinnamon brown, or grayish brown, fading to cinnamon or tan in age, at times mottled with pallid areas or nearly cream-colored overall, usually with debris and needles adhering; flesh white at first, often becoming yellowish, at least near the stalk apex in age, unchanging when cut; odor and taste not distinctive. Pores and tubes: whitish to pale yellow at first, becoming yellow to dingy yellow in age, unchanging when bruised; tubes honey yellow to olivaceous yellow or sometimes bright yellow, 3–10 mm deep. Stalk: typically short, enlarged at the base or nearly equal, base often pinched, solid; surface dry, nearly glabrous, white to pale yellow, sometimes with brown stains near the base, occasionally with inconspicuous resinous dots that become visible only in age; flesh concolorous with the cap flesh. Habitat and season: scattered, in groups, or in caespitose clusters under pines, often with only the caps visible above the needles or duff; summer and fall, also winter in the southern part of its range, most commonly occurring in early to late fall. Distribution and frequency: widely distributed throughout eastern North America; fairly common. Spore print: cinnamon brown. Microscopic features: spores 7–10 × 2.5–3.5 µm, narrowly ellipsoidal, smooth, yellowish. Edibility: edible. The flesh is soft and mild with good flavor. It can produce a laxative effect if the cuticle and tube layer are not removed and discarded before cooking. Also as for many species in the genus, the texture and flavor are improved on drying. Lookalikes: The Short-stalked Suillus is most likely to be confused with Suillus granulatus (p. 333), which has a paler-brown cap and a longer

326 · Boletes of Eastern North America stalk covered with conspicuous pinkish-tan to brownish resinous dots and smears. Suillus neoalbidipes (p. 344) has a paler cap with a wide band of whitish sterile tissue on the margin and a longer stalk. Suillus cavipes (Opat.) A. H. Sm. & Thiers = Boletinus cavipes (Opat.) Kalchbr. = Boletus cavipes Opat. = Boletus porosus (Berk.) Sacc. Common name(s): Hollow-stalked Larch Suillus, Hollow-stemmed Tamarack Jack Overview: The term cavipes means “hollow foot,” a reference to this handsome bolete’s hollow stalk. The cap surface stains red with NH4OH and blackish with KOH and is negative with FeSO4. The dry, fibrous to scaly brown cap with whitish veil remnants on the margin, hollow stalk typically with a slight ring, and association with larch are distinctive features. Cap: 3–10 cm wide, rounded to convex, becoming nearly plane in age, occasionally with a rounded umbo, margin often with hanging whitish veil remnants; surface dry, nearly suede-like, densely covered with darkbrown to yellow-brown fibers and small scales; flesh yellow, not staining Suillus cavipes

Suillus · 327 blue when exposed; odor somewhat pungent or not distinctive; taste not distinctive. Pores and tubes: pale yellow to olive yellow, unchanging when cut or bruised; pores large, angular, typically but not always elongated and radially arranged, covered with a whitish partial veil when young; tubes 2–6 mm deep. Stalk: nearly equal or enlarged downward, soon hollow, more or less reticulate at the apex, lacking resinous dots and smears, not staining blue or green when bruised, often with an inconspicuous whitish to ochraceous or brownish ring or a distinct ring zone, pale yellow on the upper portion, concolorous with the cap on the lower portion, basal mycelium white; flesh concolorous with the cap flesh. Habitat and season: scattered or in groups on the ground or among sphagnum mosses as well as in bogs, fens, and other wet areas under larch; fall. Distribution and frequency: eastern Canada south to New England and New York, west to Minnesota; occasional to fairly common. Spore print: brown. Microscopic features: spores 7–10 × 3.5–4 µm, narrowly oval to ventricose, smooth, pale brown. Edibility: edible but tastes unpleasant. Lookalikes: Boletus paluster (p. 132) is similar, but it has a pale pinkish-purple to reddish-purple cap and a concolorous solid stalk. Suillus cothurnatus

328 · Boletes of Eastern North America Suillus cothurnatus Singer Common name(s): Baggy-veiled Suillus, Booted Suillus Overview: The term cothurnatus means “high boot,” a reference to the baggy partial veil that covers the pores and part of this bolete’s stalk. The cap cuticle stains brown with KOH and a quickly fading pinkish with NH4OH. Cap: 1.5–6 cm wide, obtuse to convex, becoming broadly convex, sometimes with a low umbo, margin incurved at first, typically with hanging whitish veil fragments; surface smooth, glabrous, viscid, color variable, ochraceous to yellow brown, olive brown to grayish brown or dark brown; flesh marbled orange buff and pale yellow, not staining when exposed; odor fragrant or not distinctive; taste not distinctive. Pores and tubes: pale yellow to orange yellow, becoming brownish yellow in age, unchanging when bruised; pores irregular to radially elongated, when young covered by a thick, baggy, whitish to grayish partial veil that is rubbery and glutinous on the outer layer and that tears, leaving a ring on the stalk at maturity; tubes up to 5 mm deep. Stalk: 2–6 cm long, 5–10 mm thick, nearly equal or tapered downward, dry, solid, whitish to yellowish when young, brownish at maturity, with brownish resinous dots on the upper portion or sometimes overall; ring median to superior, collapsed, membranous, band-like, whitish to grayish, sometimes with a flaring lower edge; flesh colored like the cap flesh. Habitat and season: scattered or in groups in sandy soil under pines, sometimes on moss-covered trunks or stumps; spring through fall, year-round in the southern part of its range. Distribution and frequency: North Carolina south to Florida, west to Oklahoma and Texas; occasional to fairly common. Spore print: brown. Microscopic features: spores 8–10 × 2.5–3.5 µm, ellipsoid-oblong to subcylindric, smooth, honey brown. Edibility: edible and very good, with a lemony flavor, but the cuticle and partial veil must be removed. Lookalikes: Suillus salmonicolor (p. 348) is larger overall and has a more northern distribution, a more orange cap, a thicker veil, often salmon-orange flesh in the stalk base, and different macrochemical reactions.

Suillus decipiens (A) Suillus decipiens (B)