Boletales » Boletaceae » Nevesoporus

Nevesoporus nigrostipitatus

Nevesoporus nigrostipitatus A.C. Magnago 2022, in Magnago, et al., Mycologia 114, 607-625 (2022)

Etymology: nigrostipitatus (Latin), in reference to the blackish, shiny stipe.

Diagnosis: Differs from Tylopilus nigripes by the pinkish brown pileus, unchanging color of the hymenophore when bruised, and shorter, more ellipsoid basidiospores.

Pileus 1132 mm broad, initially parabolic and velvety, with age convex to plano-convex and subareolate toward the margin, initially brown (OAC 635), light pinkish brown (OAC 638, OAC 646) with age, dry; margin straight. Hymenophore subdecurrent, slightly depressed around the stipe, off-white (OAC 816), pale pink (OAC 668) with age; tubes 37 mm long centrally; pores 12 mm wide, angular, occasionally sublamellate near stipe, unchanging with pressure. Stipe 1828 × 35 mm, central, subequal, dark gray (OAC 901) to black (OAC 909), abruptly concolorous with tubes at extreme apex, subglabrous to velutinous, somewhat shiny, brittle. Context in the pileus off-white (OAC 816), unchanging, and blackish in the stipe. Odor and taste not obtained. Macrochemical reactions: 10% NH4OH on all surfaces negative. Basidiospores dark reddish brown in fresh deposit, 810 × 45 μm (Qm = 1.95, n = 40, s = 3), ellipsoid, pale reddish tan, inamyloid, smooth, thin-walled. Basidia 24 32 × 810 μm, clavate, hyaline, inamyloid, 4-sterigmate; sterigmata 36 μm long. Pleurocystidia and cheilocystidia similar in shape and size, 6885 × 913 μm, mostly narrowly fusoid to slightly ventricose, occasionally with one or two septa, hyaline, infrequent. Hymenophoral trama phylloporoid to subboletoid; mediostratum hyphae 49 μm wide, light yellow; lateral stratum hyphae slightly differentiated, 38 μm wide, hyaline to faintly yellow. Pileipellis a trichodermial palisade of catenulate hyphae; terminal elements tapering to the apex or clavate, 1219 × 810 μm, light brown, inamyloid. Pileus trama interwoven; individual hyphae 512 μm wide, light yellow. Stipitipellis with discrete clusters of anticlinal, cylindrical to subclavate, brownish hyphae; terminal elements 47 μm wide; caulobasidia infrequent. Stipe trama longitudinally oriented, of parallel individual hyphae 310 μm wide, light brown. Clamp connections absent.

Index Fungorum NumberIF838704

Notes: Nevesoporus nigrostipitatus is recognized in the field by the small, pinkish brown velvety pileus that is subareolate near the margin, subdecurrent, pinkish tubes that are slightly depressed around the stipe and unchanging where bruised, and slender, equal, dark gray to blackish stipe. The species is similar to Tylopilus nigripes Barbosa- Silva & Wartchow from Paraíba State in northeast Brazil (Barbosa-Silva et al. 2020). Tylopilus nigripes has similarly small basidiomata and a blackish stipe but differs from N. nigrostipitatus by the dark brown pileus, whitish to pale vinaceous context, adnate pinkish hymenophore staining red to black, and longer, more subfusoid basidiospores (8.213 × 3.55 μm, Qm = 2.63). The morphological and geographic congruences with N. nigrostipitatus suggest that T. nigripes might be better placed in Nevesoporus, but molecular data of T. nigripes are currently lacking (Barbosa- Silva et al. 2020).

The Guyanese N. exiguus resembles N. nigrostipitatus by the small basidiomata and blackish stipe but differs from it by the dark olive-green to blackish pileus that darkens with handling, adnate, white to dull pink hymenophore that rapidly blackens, and longer, higher-Q basidiospores (1013 × 45 μm, Qm = 2.35) (Henkel 1999).

Nevesoporus nigrostipitatus is similar to the Malaysian species Boletus nanus, B. psittacinus, and B. coccineianus by the small pileus width (525 mm) and lack of a blackish bruising reaction (Corner 1972). Among these species, B. psittacinus is most similar to N. nigrostipitatus in pileus width and coloration, but it has golden, pruinose tube edges and a longer stipe (3060 mm). All three of these taxa differ from N. nigrostipitatus in their villose stipe base with prominent yellow or white mycelial strands, as well as other morphological features. Among Congolian boletes described by Heinemann, none combine the characters of small size, white hymenophore, blackish stipe, and reddish brown basidiospores as seen in N. nigrostipitatus.

 

 

Figure 1. Nevesoporus nigrostipitatus. AG. ACM 1330, holotype. H. MAN 389. A. Basidiospores. B. Basidia. C. Pleuro- and cheilocystidia. D. Pileipellis terminal elements. E. Stipitipellis. FH. Basidiomata. Bars: AD = 10 μm; E = 25 μm; FH = 10 mm.

 

References:

Barbosa-Silva A., & Wartchow F., & Sulzbacher, M.A. (2020). Tylopilus nigripes sp. nov. (Boletaceae, Basidiomycota) from the Atlantic Forest of Brazil. Feddes Repertorium 131, 244250.

Corner E.J.H. (1972). Boletus in Malaysia. Singapore, Singapore: Government Printer. p. 263.

Henkel T.W. (1999). New taxa and distribution records for Tylopilus from Dicymbe forests of Guyana. Mycologia 91, 655665.

Magnago, A. C., & Alves-Silva, G., & Henkel, T. W., & da Silveira, R. M. B. (2022). New genera, species, and combinations of Boletaceae from Brazil and Guyana. Mycologia 114, 607-625.

 

About Basidiomycota

The webpage Basidiomycota provides an up-to-date classification and account of all genera of the phylum Basidiomycota.

 

Supported by 

Thailand Science Research and Innovation (TSRI)

project entitled:

"Macrofungi diversity research from the Lancang-Mekong Watershed and surrounding areas"

(Grant No. DBG6280009)

Contact

  • Email: basidio.org@yahoo.com
  • Addresses:
    Mushroom Research Foundation, 292 Moo 18, Bandu District,
    Muang Chiangrai 57100, Thailand
  • The State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No.3 1st Beichen West Rd., Chaoyang District, Beijing 100101, P.R. China


Published by the State Key Lab of Mycology, Institute of Microbiology, Chinese Academy of Sciences and
Mushroom Research Foundation
Copyright © The copyright belongs to the Curators. All Rights Reserved.