Boletellus piakaii T.W.Henkel & Fulgenzi

Filed As

Boletaceae
Boletellus piakaii T.W.Henkel & Fulgenzi ( isotype )

Collector(s)

T. W. Henkel 8728, 02 Jul 2004

Location

Guyana. Potaro-Siparuni. Pakaraima Mountains, Upper Potaro River, in Dicymbe plot 1.

Habitat

Rain forest. Dicymbe corymbosa. Solitary to scattered. Root mats of D. corymbosa.

Description

Pileus (25) 40-72 mm broad, convex to planoconvex, dark brown (6F8) throughout when young to olive brown (5E6-5E8-5F8) to olive-yellow (4A8-4B8-4C8-4D8) with age, rugulose to rugose, minutely granular (under 10× lens), moist, margin slightly inrolled and entire; trama 1-2 mm thick at margin, 3-5 mm over tubes, 6-12 mm above stipe, offwhite, immediately green-blue (26D5) upon exposure, fading to dingy-green (28D6) and yellowing after several minutes, solid; tubes 3-6 mm long at margin, 8-13 mm centrally, 6-7 mm at stipe, of irregular lengths, narrowly and deeply depressed around stipe, with short decurrent teeth 1-2 mm long, light olive-yellow (3A7-3B7), quickly blue-green (20F8-24F8) upon exposure, eventually fading to dull brown; pores yellow (2A8) when immature to oliveyellow (3A7-3B7-4B8-4C8), immediately blue-green (24F8) with pressure, then fading gradually to green (27F8), green-brown (4E6), and eventually brown (6E8-6F8), 1-1.5 per mm, subisodiametric to angular; stipe (60)98-120 × 7.13 mm, subequal, enlarging gradually to 11-13 mm broad at base, ground tissue yellow-tan (4A5-4B5-4C8), overlaid with pinkish brown (6D5-6E5-6D4-6E4) to red-maroon (7E6-7E7-7D8-8E7) longitudinal striations throughout, these darkening with age and handling, apex with light red-brown (7A5) band, lower 20-25 mm with densely matted dark-brown (7F4-8F2) tomentum; subtending hyphae concolorous and often associated with ectomycorrhizal rootlets; trama off-white to yellow (4A7-4B7) to brown (7D5-7E5-7D8-8E7) with age, transiently bluing upon exposure, solid; odor minimal, pleasant; taste mild. Basidiospores dark olive-brown (4F8-5F8) in medium to heavy deposit, 9.8-12.4 ×5-7.4 µm (mean Q = 1.69), goldenolive in H2O and KOH, inamyloid, amygdaliform, 1-2 guttulate, with 18-22 longitudinal ridges; ridges < 1 µm tall, repeatedly dichotomously forked, converging at both poles, transverse striae absent; hilar appendage 0.5-0.9 µm long; basidia 32.4-46 × 13.1.15.6 µm, clavate, wall hyaline in H2O and KOH, with numerous refractive globules, these light golden in H2O, lighter in KOH, 4-sterigmate; sterigmata 3.2-5 µm long; pleurocystidia 37-69 × 8.4-12.4 µm, ventricose-rostrate, frequent, arising from the subhymenium, projecting 21-30.8 µm beyond the hymenial palisade, hyaline, thin-walled; cheilocystidia absent; hymenophoral trama boletoid, strongly divergent; mediostratum 19.7.49.4 ìm wide, of many thin-walled, nearly parallel hyphae, golden in H2O, lighter and gelatinized in KOH; lateral stratum hyphae 7.4-12.4 µm wide, hyaline, nongelatinized; pileipellis a cystoderm of irregularly globose to subangular cells; these thin-walled, faint-golden in H2O, hyaline in KOH; pileus trama of interwoven hyphae, many with thickened walls; individual hyphae 4.4-11.1 µm wide, wall up to 0.5 µm thick, regularly septate, devoid of contents, in mass light golden in H2O, lighter in KOH; stipitipellis an interwoven trichodermial palisade of cylindrical elements with inflated terminal cells, in mass golden orange in H2O, lighter in KOH; terminal cells projecting 22.5-40 µm, cylindrical to clavate, occasionally ventricose to mucronate, these concentrated on longitudinal striations; subpellis hyphae interspersed with external burgundy acerose crystals; stipe trama of densely packed parallel hyphae, in mass faint golden in H2O, lighter in KOH; individual hyphae 4-9.6 µm wide, hyaline in H2O and KOH, regularly septate; clamp connections absent. Macrochemical reactions - NH4OH rapidly light red-brown (8D6) on pileus, soon darkening, burgundy (9E8) on stipe ground, black on longitudinal striations, light burgundy (9D6) on stipe trama; KOH light orange-brown (7C6) to burgundy (8F7) on pileus, burgundy (8F7) on stipe, red-brown (8D8) on pileus and stipe trama; FeSO4 dark grey-green (28F4) on pileus, dark green (29F5) on tube mouths, dark green (28F8) on stipe, yellow-green (29D6) on stipe trama.

Identifiers

NY Barcode: 1034438

Occurrence ID: 6c419442-d20a-4ef2-b5cc-a47e21ecd0bd

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