Tylopilus orsonianus Fulgenzi & T.W.Henkel

Filed As

Boletaceae
Tylopilus orsonianus Fulgenzi & T.W.Henkel

Collector(s)

T. W. Henkel 8106, 12 May 2001

Location

Guyana. Potaro-Siparuni. 4 km SW of Potaro base camp near Dicymbe plot 3.

Habitat

rainforest. Dicymbe corymbosa. solitary to scattered. root mat.

Description

Pileus 26–66(98) mm broad, convex to planoconvex, brown throughout (6E6–7F6) to tannish brown (4B4–4B7) with age, velutinous, becoming minutely areolate when mature (under lens), dry, margin slightly inrolled and entire; trama 1–3 mm thick at margin, 4–10 mm over tubes, 5–17 mm above stipe, white to cream (3A3) to light grayish yellow (3B3), unchanging, solid. Odor fragrant; flavor mild, nutty (not bitter). Tubes 1–3 mm long at margin, 3–9 mm centrally, 1–4 mm at stipe, narrowly and deeply depressed around stipe, cream yellow (3A4) to light yellow (3B4–4B4), slowly and slightly browning with exposure; tube mouths cream yellow (3A3–3A4) to grayish yellow (4B3), browning slightly with pressure; pores 1–2 per mm, isodiametric to subovate. Stipe 48–111(140) mm 3 11–34(42) mm centrally, 6.5–22(30) mm at apex, 6–23 mm at base, subequal, tapering gradually upward, strongly attenuated at extreme base, occasionally curving, olivaceous brown throughout (5E6) to dark brown (6F5–6F8); extreme apex light grayish yellow (3B4) to light grayish orange (4B5), smooth, finely pubescent under lens, coarsely reticulate over upper one-third to two-thirds; reticulum less pronounced toward base, lower onequarter with a low, densely matted dark grayish brown tomentum (5E4–5E5); extreme base with white to cream mycelium, occasionally subtended by grayish brown rhizomorphs and brown ectomycorrhizae; trama cream in upper three-quarters, lower onequarter olivaceous brown (4E4) to dark brown (5F6), discoloring throughout along larval tunnels (5F6), otherwise unchanging, solid, less so with age. Basidiospores flesh pink (6B2–6C2–6C3) in light to medium deposit, 11–14.5 mm 3 4.9–7.4 mm (mean Q 5 2.31), ellipsoid to subfusiform, faint pink in H2O, hyaline in KOH, inamyloid, 1–2-guttulate; hilar appendage 0.4–0.8 mm long; wall 0.5–0.9 mm thick, smooth. Basidia 24.7–41.3 mm 3 9.6–16.9 mm, clavate, thin walled, hyaline in H2O and KOH, 4-sterigmate. Hymenial cystidia 39.5–71.6 mm 3 5.7–12.4 mm, ventricose to ventricose-rostrate, occasionally more cylindrical, frequent, arising from the subhymenium, projecting 17–40 mm above the hymenial palisade, hyaline, devoid of refractive contents. Hymenophoral trama boletoid; mediostratum 24.7–44.5 mm wide, of many narrow parallel hyphae, these yellow orange in H2O, gelatinized and light yellow orange in KOH, lateral stratum hyphae 4.0–5.7 mm wide, hyaline, nongelatinized, strongly divergent. Pileipellis an interwoven trichodermial palisade of cylindrical elements with inflated terminal cells, in mass light golden brown in H2O, lighter in KOH; terminal cells 15.3–49.4 mm 3 7.4–12.4 mm wide, faint golden brown in H2O, hyaline in KOH, inamyloid, cylindrical to mucronate to ventricose-rostrate, occasionally globose to clavate. Pileus trama interwoven; individual hyphae 4–5 mm wide, thin walled, light golden in H2O, hyaline in KOH, regularly septate. Stipitipellis a highly interwoven trichodermial palisade, dark brown in mass in KOH; individual hyphae 6.3–9.4 mm wide; terminal cells golden brown in H2O, lighter in KOH, thin-walled, clavate to cylindrical, occasionally broadly mucronate; subpellis hyphae with spirally arranged, yellowish encrusting pigments; upper stipe reticulum with infrequent basidia. Clamp connections absent. Macrochemical reactions: NH4OH negative on pileus surface, burgundy to black on trama of stipe base; KOH yellowing on pileus surface, burgundy to black on trama of stipe base.

Identifiers

NY Barcode: 1115440

Occurrence ID: a35d88ce-71d9-426c-8395-43615f4c99a3

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