Phylloporus rimosus Bandala, Montoya & Garay

Montoya, Leticia, Garay-Serrano, Edith & Bandala, Victor M., 2019, Two new species of Phylloporus (Fungi, Boletales) from tropical Quercus forests in eastern Mexico, MycoKeys 51, pp. 107-123 : 107

Phylloporus rimosus Bandala, Montoya & Garay sp. nov. Figs 2a, b, 3, 4

Holotype.

MEXICO. Veracruz: Municipality of Coatepec, Vaquería, gregarious in soil, under Quercus oleoides Schltdl. & Cham., 27 June 2012, Montoya 4834 (XAL).

Diagnosis.

Recognized by the combination of pileus vinaceous to grayish-vinaceous, surface becoming rimose-areolate with development, the stipe apex with ribbed appearance and scabrous or even with tiny rigid scales and gills staining blue. Its stature (pileus 27-80 mm diam., stipe 27-80 × 7-12 mm), basidiospores and pleurocystidia size and shape, prevents confusion with P. purpurellus Singer or with P. scabripes B. Ortiz & M.A. Neves.

Gene sequences ex-holotype.

MK226546 (ITS), MK226554 (LSU), MK314102 (tef-1α).

Etymology.

Referring to the rimose pileus surface.

Description.

Pileus 27-80 mm diam, convex to plane-convex, at times faintly depressed at center or even infundibuliform; surface velvety, uniform but frequently rimose-areolate, or fracturing and forming rivulose patches, cracked when seen under lens, vinaceous to grayish-vinaceous (7D4-D5, 7C4; 5YR 3/4, 4/3, 4/4-25Y 6/6), darker in some areas especially towards the margin, or yellowish, reddish-yellow, reddish-brown or even yellowish-beige (10YR 5/4, 6/6) in other parts especially towards the center, some specimens even reddish-vinaceous (7E8-E7) with brownish tinges (7D6-6E8), mature specimens fading to brownish when exposed to the sun; margin slightly incurved, edge entire, at times undulate. Lamellae subdecurrent to decurrent, 9-15 mm broad, close, bright yellow (3A7, 5A6-A7; 5Y8/8; 4A16), mustard yellow with age (4A6-A7; 4B7-B8), staining blue or greenish-blue when handled, stains becoming reddish or brownish-vinaceous after several minutes, old specimens or specimens long exposed to the sun developing reddish spots at lamellae sides or even dark brownish red or brown at edge; somewhat sinuous when the hymenophore is seen frontally, veined or anastomosed mostly in the area below the pileus and intervenose or even somewhat labyrinthiform, especially when young; lamellullae of different sizes, edge entire. Stipe 27-80 × 7-12 mm, cylindrical, curved, somewhat sinuous, compact, apex with ribbed appearance by decurrent lines of the lamellae, surface pruinose, scabrous or even with tiny rigid scales, cracked after long exposure to the sun, beige (10YR 6/6-8) or pale yellow (4A/2), or whitish at the bottom of the surface and covered with a reddish or oxide-red (25YR 4/6) pruina, at the middle area reddish-beige (8D16), at times caespitose. Basal mycelium whitish-cream with some yellow spots or even mustard yellow (5Y8/6). Context yellow, staining pinkish or pinkish-brown. KOH 3% reddish (10YR 3/6 to 2.5YR 3/4) on pileus, stipe surface and context; NH4OH 10% greenish-blue (5Y 2.5/1) on pileus surface, the center of the stain becoming reddish (2.5YR 3/6), brownish at the hymenium, negative in the context and faintly green or negative on stipe surface. Odor mild to slightly citric. Taste mild.

Basidiospores (9-) 9.5-14 (-15) × 3.5-5 µm, X‒ = 11-12.3 × 4.3-4.6 µm, Q‒ = 2.5 2.8 µm, subfusiform, with suprahilar depression, somewhat ventricose, apex attenuated, yellow to amber yellow in KOH, wall slightly thickened (up to 0.5 µm thick). Basidia 29-50 (-55) × 7-10 (-11) µm, clavate, tetrasporic, rarely trisporic, hyaline, thin walled, unclamped. Pleurocystidia 42-105 (-120) × 9-27 µm, narrowly to broadly utriform, at times cylindrical or subclavate, rarely sphaeropedunculate (52-58 × 20-23 μm), thin-walled, at times thickened in some areas, some with incrustations, hyaline, abundant, unclamped. Cheilocystidia (33-) 34-70 (-75) × 8-17 (-19) µm, narrowly utriform, hyaline, thin-walled, at times thickened towards the apex, unclamped. Pileipellis a trichodermis, with anticlinally oriented hyphae, tightly interwoven, frequently disposed in mounds, hyphae 8-16 µm broad, wall slightly thickened (up to 1 µm), hyaline yellowish-brown; terminal elements 23-64 × 8-14 µm, cylindrical, slightly inflated, other or clavate, pale yellowish-brown. Pileus trama hyphae 5-16 µm broad, in a lax interwoven arrangement, hyaline, thin walled. Hymenophoral trama arranged in a more or less regular central strand and somewhat divergent on both sides of the strand, with cylindrical hyphae 7-19 µm broad; some slightly inflated, hyaline, thin-walled, unclamped.

Habitat.

In soil, solitary or gregarious, in tropical oak forest, under Quercus oleoides and Q. sapotifolia .

Additional studied material.

MEXICO. Veracruz: Alto Lucero Co., NE Mesa de Venticuatro, 4 Oct 2016, Garrido14; 19 Sep 2017, Gutiérrez 37. Zentla Co. Road Puentecilla-La Piña, 2 July 2009, Ramos 195. Around town of Zentla, 15 June 2016, Montoya 5232a; Montoya 5238; 23 June 2016, Gutiérrez 5, Hervert 84; 30 June 2016, Cesar 61, Hervert 93; 6 July 2016, Caro 69; 30 Aug 2016, Garrido 3; 24 Aug 2017, Garay 368; 7 Sep 2017, César 84 (all at XAL).