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

Figs 3 , 8 a, b

Suillus alboater (Schwein.) Kuntze, Revis. gen. pl. (Leipzig) 3 (3): 535. 1898.

Tylopilus alboater (Schwein.) Murrill , Mycologia 1 (1): 16. 1909.

Porphyrellus alboater (Schwein.) E. - J. Gilbert , Les Bolets: 99. 1931.

Basionym.

Boletus alboater Schwein. , Schr. naturf. Ges. Leipzig 1: 95. 1822.

Description.

Basidiomata medium to large sized. Pileus 4.5–13.5 cm broad, convex to plano-convex to plane, dry, subvelutinous to matte, black to dark gray to dark brown, becoming gray, becoming finely areolate with age, with even and entire margin; context white, up to 3 cm thick, slowly light pinkish orange or red to pinkish gray, then black when injured, with mild odor and taste. Hymenophore adnate to adnexed; surface white at first becoming pinkish vinaceous, staining pinkish orange to reddish brown then black when injured; tubes up to 10 mm long. Stipe 5–9 × 1–3 cm, equal to subclavate, dry, finely subpruinose, sometimes obscurely ridged below, white above and black below at first, eventually black overall, white to pale grayish at base; context white above, gray to black below, becoming black with age. Spore print pinkish vinaceous. Taste and odor mild ( Coker and Beers 1943; Singer 1947; Snell and Dick 1970; Smith and Thiers 1971; Roody 2003; Phillips 2005; Moore et al. 2007; Bessette et al. 2024; our observation).

Basidia 20–31 × 9.5–12 μm, clavate, thin-walled, 4 - spored, hyaline to yellowish in KOH. Basidiospores [60 / 2 / 1] (8) 8.5–10.5 (11) × 4–5 μm, [Q = (1.78) 1.89–2.63 (2.75), Q m = 2.18 ± 0.17], 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 24–46 × 8–18 μm, fusiform or subfusiform, thin-walled, yellowish brown to brownish in KOH, yellow-brown to brown in Melzer’s reagent; surface without encrustations. Pleurocystidia 39–56 × 13–17 μm, morphologically similar to cheilocystidia. Pileipellis a trichoderm, composed of 4–8.5 μm wide filamentous interwoven hyphae, yellowish brown to brown in KOH, and brown to dark brown in Melzer’s reagent; terminal cells 22–58 × 4–6.5 μm, clavate to subcylindrical or fusiform, thin-walled. Pileal trama composed of thin-walled hyphae; hyphae 4.5–9 μm wide, hyaline to yellowish in KOH, brownish to yellowish brown in Melzer’s reagent. Clamp connections absent in all tissues.

Habitat and distribution.

Solitary, scattered to gregarious under trees of the genera Quercus , Fagus , Betula , Carya ; currently known from eastern United States, New York to northern Florida, west to Missouri.

Specimen examined.

USA • New York, Bronx Co., Bronx, New York Botanical Garden, River Way & Snuff Mill Rd. , ca 20 m, 40.8586°N, 73.8776°W, 13 August 1984, Halling 3794 ( NY 45157 ) , 19 August 1984, Halling 3803 ( NY 45194 ) , 5 September 1984, R. E. Halling 3819 ( NY 45190 ) , 24 July 1989, Halling 6277 ( NY 45187 ) ; Azalea Way , 40.8624°N, 73.8781°W, 10 September 1984, Halling 3841 ( NY 45189 ) , 7 July 1989, Halling 6246 ( NY 45197 ) , 9 July 1992, Halling 6866 ( NY 45196 ) , 1 August 1992, Halling 6883 ( NY 45182 ) , 40.8624°N, 73.8781°W, 7 July 1985, Halling 4431 ( NY 45199 ) , 40.8619°N, 73.8777°W, 50 m, 5 August 1985, Halling 4493 ( NY 45198 ) ; near Twin Ponds , 40.8665°N, 73.8754°W, 30 July 1988, Halling 5964 ( NY 45200 ) , 4 August 1988, Halling 5971 ( NY 45195 ) , 12 June 1991, Halling 6542 ( NY 45186 ) , 27 August 1991, Halling 6633 ( NY 45191 ) ; east end of eastern Twin Pond , 40.8671°N, 73.8754°W, 21 August 1985, Halling 4549 ( NY 14583 , NY 14584 ) , 8 September 2008, Halling 9013 ( NY 1034447 ) , 23 August 2011, Halling 9601 ( NY 1193926 and KUN-HKAS 147016 ) ; 40.8667°N, 73.8753°W, 35–36 m, 14 July 2016, Halling 10083 ( NY 02685939 ) , 9 August 2017, Halling 10154 ( NY 02861405 ) , 3 August 2018, Halling 10176 ( NY 02072595 ) , 13 September 2019, Halling 10186 ( NY 02072672 ) .

Typification of the name Boletus alboater .

Neoporphyrellus alboater was originally described as Boletus alboater from Bethlehem, Pennsylvania, USA, by Schweinitz (1822). Since then, typification has not been verified, even though # 864 was the number applied to a specimen by Schweinitz. We have tried to locate the original material in PH for lectotypification but without success. Also, we have checked K, FH, BPI, and UPS but failed to find that specimen. In PH, there is another specimen ( PH 00078766) that was collected by Persoon and verified by Schweinitz as Boletus alboater . Persoon clearly did not collect in the USA, so it is highly unlikely that the identification is correct. Also, based on current knowledge, B. alboater has not been documented in Europe. According to information listed on MycoPortal. org, another specimen in PH (00078756) listed as Boletus sp. , determined by Schweinitz, with an “ ID Remarks ” as “ Boletus alb . ” The collector is listed as unknown, there are no locality data, and a verbatim date of “ 1805-01 - 02 ” is cited without a known collector number. Thus, due to a lack of valid original material, we have proposed here a neotype in NY with an isoneotype in KUN. As we noted above, the NYBG site is only ± 150 km east of the type locality cited later by Schweinitz (1832).

Type.

( Neotype designated here, Figs 3 , 7 a, b , Mycobank No.: MBT 10026353): USA • New York, Bronx Co., Bronx, New York Botanical Garden, east end of eastern Twin Pond , 23 August 2011, Halling 9601 ( Neotype: NY 1193926 , GenBank Acc. Nos. OP 771514 for nrLSU, OP 765296 for rpb 1, OP 762644 for rpb 2, OP 750052 for tef 1 - α; Isoneotype: KUN-HKAS 147016 ) .

Notes.

Neoporphyrellus alboater is characterized by its black to dark gray to dark brown pileus, which is areolate with age; white context slowly turning light pinkish orange or red to pinkish gray, then black when injured; finely subpruinose stipe, which is white above and black below at first and eventually black overall; white to pinkish vinaceous hymenophore becoming pinkish orange to reddish brown, then black when bruised; smooth basidiospores; and trichoderm pileipellis ( Coker and Beers 1943; Singer 1947; Snell and Dick 1970; Smith and Thiers 1971; Roody 2003; Phillips 2005; Moore et al. 2007; Bessette et al. 2024). This species shares basidiospore size and the same discoloration reaction when injured with An. cystidiatus ( Li and Yang 2021) . However, An. cystidiatus differs from N. alboater in its grayish red to brownish red or ruby red pileus, which is slightly darker in the center, and its epithelial pileipellis composed of 8–21 μm wide inflated concatenated cells. The white hymenophore when young and dull pink when mature and the sometimes slightly reticulated stipe apex of N. alboater are similar to those of N. atronicotianus . Moreover, both of these species are phylogenetically related. However, N. atronicotianus has a finely tomentose pileus and stipe, a bright brown hymenophore, a reddish-brown spore print, relatively large basidia (31–46 × 7.5–9.5 μm), and narrow pleurocystidia and cheilocystidia (9–12 μm and 6–9 μm wide, respectively).

Figures

Figure 3. Microscopic features of Neoporphyrellus alboater (NY 1193926). a Basidiospores b Basidia, basidioles and pleurocystidium c Cheilocystidia d Pleurocystidia e Pileipellis. Scale bars: 20 μm.

Figure 7. Microscopic features of Abtylopilus indonesiensis (NY 1393740, type). a Basidiospores b Basidia c Cheilo- and pleurocystidia d 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/).