Pseudoboletus silvaticus A. Cortés-Pérez & V. Ram., 2023

Cortés-Pérez, Alonso, Ramírez-Guillén, Florencia, García-Jiménez, Jesús, Ramírez-Cruz, Virginia, Villalobos-Arámbula, Alma Rosa, Reynaga, Dolores Marina Barragán & Guzmán-Dávalos, Laura, 2023, Pseudoboletus silvaticus (Boletaceae, Basidiomycota), a new species from Mexico, Phytotaxa 589 (1), pp. 27-38 : 32-35

Pseudoboletus silvaticus A. Cortés-Pérez & V. Ram. -Cruz sp. nov. Figs. 2‒3

Mycobank No.: MB847638

Diagnosis:—Pileus convex, viscid, yellowish brown. Stipe central or eccentric, cylindrical with a swollen base, surface orangish yellow or pale yellow, with reddish brown or olive brown longitudinal fibrils or adpressed squamules. Basidiospores 11.0‒14.0 × 4.5‒5.5 μm, Q = 2.09‒2.88, cylindrical. Pileipellis an ixocutis, with intricate, repent or some semi-erect, 2‒7 μm diam. hyphae, hyaline or pale yellow, thin-walled with or without incrustations. Stipitipellis a cutis, with repent hyphae, terminal cells 7‒50 × 3‒12 μm, clavate to cylindrical. Growing on Scleroderma nitidum Berkeley (1854: 173) .

Etymology:—‘ silvaticus ’ in Latin, refers to the habitat of the species, in the forest.

Holotype:— MEXICO. Veracruz: Municipality of Santiago Tuxtla , elev. 1077 m, 18° 34′ 47.45′′ N, 95° 11′ 40.87′′ W, gregarious or solitary, growing on Scleroderma nitidum in tropical montane cloud forest, 8 July 2017, A. CortésPérez 1870 (holotype XAL!, isotype ITCV!). GenBank: ITS ( OQ452992 ), 28S ( OQ463831 ), tef–1α ( OQ476659 ).

Pileus 20‒42 mm diam., initially hemispherical expanding to convex or broadly convex, surface viscid, glabrous, pale yellow (4E3) to yellowish brown (5E7) with olive (2F7) to olive brown (4F8) tints, sometimes darker toward the center, with irregular orange brown stains; margin inflexed to straight. Context 6‒8 mm thick in the disk, 2‒3 mm in the margin, flesh, whitish or yellowish white (2A2). Tubes 3‒6 mm long, adnate to sinuate, chrome yellow (3A8) to olive yellow (2C7), unchanged when bruised; pores 0.5‒1.0 mm diam., angular, light yellow (2A5) when young, later chrome yellow (3A8) to dingy yellow (3B7), unchanged when bruised, brownish orange (6C7) to dark brown (6F7) with 3% KOH. Stipe 40‒60 × 5‒7 mm in the middle, × 6-8 mm at the apex, × 8‒13 mm at the base, central or eccentric, cylindrical with a slightly swollen base, surface pale yellow (4E3) to orangish yellow (6C7), with reddish brown (8E7) or olive brown (47F) longitudinal fibrils, and reddish brown completely adpressed squamules (8E7); whitish mycelium in the base; context solid, fleshy, pale yellow (4E3), pale orangish brown (4B7) to brownish yellow (5C7) with 3% KOH. Odor and taste not recorded.

Basidiospores 11.0‒14.0 (‒15.0) × 4.5‒5.5 (‒5.8) μm, Q = 2.09‒2.88, cylindrical, subfusiform, with suprahilar depression, smooth (under light microscope), yellowish to yellowish brown, thick-walled (0.4‒0.6 μm thick). Basidia (25‒) 30‒39 × 9‒11 μm, clavate, 4‒spored with sterigmata 3‒6 μm long, hyaline, some yellowish. Basidioles 16‒30 × 9‒11 μm, clavate to cylindrical, hyaline, some with refringent granulose content. Pleurocystidia (43‒) 50‒63 × (7‒) 8‒12 (‒14) μm, narrowly fusiform, apex obtuse or mucronate, hyaline to yellowish, thin-walled. Cheilocystidia (37.0‒) 45.0‒75.0 (‒78.0) × (6.5‒) 8.0‒10.0 (‒11.0) μm, narrowly fusiform, apex obtuse or mucronate, hyaline to yellowish, thin-walled. Subhymenium ramose, non-gelatinous, hyaline. Hymenophoral trama divergent, gelatinous, hyphae 1.5‒11.0 μm diam., some inflated, thin-walled, without incrusted pigment, hyaline. Pileipellis an ixocutis, hyphae 2‒7 μm diam., intricate, repent or some semi-erect, thin-walled, with or without incrusted pigment, hyaline to yellowish. Pileus trama interwoven, hyphae 3‒12 μm diam., thin-walled, hyaline. Stipitipellis a cutis of repent hyphae, terminal cells 7‒50 × 3‒12 μm, clavate to cylindrical, thin-walled, with or without incrusted pigment, hyaline or yellowish; medullar hyphae 2‒16 μm diam., parallel, thin-walled, hyaline. Clamp connections absent.

Habit, habitat, and known distribution:—Solitary or gregarious in tropical montane cloud forest associated with Scleroderma nitidum and possibly with Quercus skinneri Bentham (1841: 116) , so far only known in Mexico.

Additional specimens examined:— MEXICO. Veracruz: Municipality of Santiago Tuxtla, volcano of San Martín , 1077 m elev., 18° 34′ 47.45′′ N, 95° 11′ 40.87′′ W, 8 July 2017, A. Cortés-Pérez 1864 ( XAL); A. Cortés-Pérez 1867 ( Scleroderma nitidum, XAL ).

Figures

FIGURE 2. Macro and micromorphology of Pseudoboletus silvaticus. A. Basidiomata (A. Cortés-Pérez 1870, holotype, photo: A. Rockefeller). B. Basidiospores. C. Pleurocystidia. D. Cheilocystidia. E. Pileipellis. F. Terminal cells of the stipe. G. Stipitipellis (A. Cortés-Pérez 1870, holotype). Scale bars: A= 15 mm, B–D, F= 10 µm, E–G= 20 µm.

FIGURE 3. Microscopic features of Pseudoboletus silvaticus. A. Basidiospores. B. Basidia. C. Pleurocystidia. D. Cheilocystidia (A. Cortés-Pérez 1870, holotype). Scale bar= 10 µm.