Neoporphyrellus atronicotianus (Both) Yan C. Li, J. Li, Halling, Osmundson & Zhu L. Yang, 2025

Li, Jin, Halling, Roy E., Osmundson, Todd W., Yang, Zhu L. & Li, Yan-Chun, 2025, Global diversity of the Tylopilus alboater complex (Boletaceae, Boletales): new genus and species, and typification of the name Boletus alboater, IMA Fungus 16, pp. e 159676-e 159676 : e159676-

Neoporphyrellus atronicotianus (Both) Yan C. Li, J. Li, Halling, Osmundson & Zhu L. Yang comb. nov.

Figs 4 , 8 c, d

Basionym.

Tylopilus atronicotianus Both , Bull. Buffalo Soc. Nat. Sci. 36: 216. 1998

Description.

Basidiomata medium to large sized. Pileus 7.5–20 cm in diameter, hemispherical to broadly convex or flattened; surface dry, smooth, light brown to olive-brown, becoming darker in color when matured; context whitish, staining pink to pinkish red at first, and then becoming black when injured. Hymenophore surface initially whitish, staining red at first and then blackish when injured; pores angular, up to 1.5 mm wide; tubes up to 8 mm long, bright brown, staining reddish at first and then black when injured. Stipe 6–12 × 1.5–4.5 cm, clavate to subcylindrical, solid, grayish to dark brown, almost black at the base, surface finely tomentose, sometimes finely reticulate near apex; context white, pink to pinkish-red at first, and then becoming black when injured. Spore print reddish-brown ( Both 1998; Bessette et al. 2000, 2024; and our observation).

Basidia 31–46 × 7.5–9.5 μm, clavate, thin-walled, 4 - spored, hyaline to yellowish in KOH. Basidiospores [40 / 2 / 2] 7.5–10.5 × 3.5–5 μm [Q = 1.78–2.38, Q m = 2.14 ± 0.09], subfusiform in profile view with slight suprahilar depression, elongated to fusiform in ventral view, smooth, slightly thick-walled (up to 0.5 μm), hyaline to brownish in KOH, brown to yellowish brown in Melzer’s reagent. Hymenophoral trama boletoid; hyphae cylindrical, hyaline to yellowish in KOH, yellowish to yellow in Melzer’s reagent. Cheilocystidia 32–47 × 6–9 μm, fusiform or subfusiform, thin-walled, yellowish brown to brownish in KOH, yellow-brown to brown in Melzer’s reagent; surface without encrustations. Pleurocystidia morphologically similar to cheilocystidia but much bigger, 38–76 × 9–12 μm. Pileipellis a trichoderm, composed of 3.5–7 μm wide filamentous interwoven hyphae, yellowish brown to brownish in KOH, and brown to yellow-brown in Melzer’s reagent; terminal cells 11.5–76 × 3.5–5.5 μm, clavate to subcylindrical, thin-walled. Pileal trama composed of thin-walled hyphae; hyphae 4.5–9 μm wide, hyaline to yellowish in KOH, yellow to yellowish brown in Melzer’s reagent. Clamp connections absent in all tissues.

Habitat and distribution.

Solitary on the ground of deciduous forest dominated by red oak ( Quercus rubra ), beech ( Fagus sp. ), and hemlock ( Tsuga sp. ); currently known in the United States from New York to West Virginia.

Specimen examined.

USA • New York, Erie Co., North Collins, Town Park , alt. ca 1319 m, 42.5953°N, 78.9411°W, August 1983, E. E. Both 2480 ( NY 815170 , paratype) ; New York, Erie Co., North Collins, Ukrainian Camp , alt. ca 1319 m, 42.5953°N, 78.9411°W, 18 September 1981, B. Both 2358 ( NY 815171 , paratype) .

Notes.

Neoporphyrellus atronicotianus was originally described from New York and is currently known from the eastern USA ( Both 1998; Bessette et al. 2000, 2024). It is characterized by its light brown to olive-brown pileus, whitish context staining pink to pinkish-red and then becoming black when injured, whitish hymenophore staining red at first and then blackish when injured, smooth basidiospores, and trichodermium pileipellis ( Both 1998; Bessette et al. 2000, 2024; and our observation). This species is morphologically similar to T. alpinus Yan C. Li & Zhu L. Yang , as both of them have an olive-brown pileus, whitish context, whitish hymenophore, and reticulum at the upper part of the stipe. However, T. alpinus differs from N. atronicotianus in its context staining pale red to grayish red but without any black or blackish tinges when injured, hymenophore staining a brownish red to grayish red or orange-brown tinge when bruised, and relatively long basidiospores (13–14.5 μm) ( Li and Yang 2021). Neoporphyrellus atronicotianus is phylogenetically closely related to N. alboater and N. sinoalboater . However, N. alboater has a black to dark gray to dark brown pileus, which is areolate with age, a finely subpruinose stipe, a white to pinkish vinaceous hymenophore, and relatively broad cheilocystidia measuring 24–46 × 8–18 μm and pleurocystidia measuring 39–56 × 13–17 μm. While N. sinoalboater differs from N. atronicotianus in its gray to brownish gray pileus and relatively small pleurocystidia (34–55 × 8–14 μm).

Figures

Figure 4. Microscopic features of Neoporphyrellus atronicotianus (NY 00815170, paratype). a Basidiospores b Basidia, basidioles and pleurocystidium c Cheilocystidia d Pleurocystidia e Pileipellis. Scale bars: 20 μm.

Figure 8. Basidiomata of “ Tylopilus alboater ” from different regions. a, b N. alboater from North America (NY 1193926, images by Halling) c, d N. atronicotianus from North America (NY 815171, images by Both) e, f Neoporphyrellus sinoalboater from China (e KUN-HKAS 145312, type; f KUN-HKAS 145313) g Abtylopilus australiensis from Australia (NY 2049854, image by Osmundson) h Ab. indonesiensis from Indonesia (NY 1393740, image by Halling) (c – h from https://sweetgum.nybg.org/science/vh/specimen-list/).