Retiboletus subg. Retiboletus

Li, Jin, Wang, Zhen, Liu, En-De, Yang, Zhu L. & Li, Yan-Chun, 2022, Morphological and molecular data reveal Retiboletus cyanescens sp. nov. and the new subgenus Nigroretiboletorum (Boletaceae), Phytotaxa 572 (3), pp. 232-242 : 236-237

Retiboletus subg. Retiboletus

Type: Retiboletus ornatipes (Peck) Binder & Bresinsky, Feddes Repert 113(1–2): 37 (2002).

Diagnosis: Retiboletus subg. Retiboletus differs from R. subg. Nigroretiboletorum by its yellow to light yellow hymenophore and context, which is unchanging or staining yellow to yellowish brown when injured.

Description: Basidiomata small to large-sized. Pileus subhemispherical to broadly convex, sometimes applanate; surface dry, velutinous to tomentose to matted tomentose, yellowish brown, gray brown to brown or yellow, sometimes with olive tinge; margin incurved; context pale yellow to light yellow, unchanging or staining yellow to yellowish brown in color when injured. Hymenophore poroid, adnate or slightly depressed around apex of stipe; pores angular pale yellow, yellow, to light yellow, usually changing yellowish brown to brown or pale orange when injured; tubes yellowish to light yellow, usually changing yellowish brown, pale brown when injured. Stipe central, subcylindric, solid, usually flexuous; surface dry, yellowish, yellow to brownish yellow, prominently and coarsely reticulate nearly to base or the upper; reticulum brownish black or yellow to light yellow; context yellow, unchanging or changing vivid yellow or yellowish brown in color when injured; annulus absent. Basal mycelium yellow. Odor indistinct. Basidiospores smooth, subfusiform to ellipsoid; Cheilo- and pleurocystidia abundant, fusiform or subfusiform; Pileipellis a trichoderm composed of vertically or interwoven thin-walled hyphae; Stipitipellis hymeniform, composed of thin-walled hyphae with narrowly or broadly clavate, subfusiform or fusiform terminal cells. Clamp connections absent in all tissues.

Ecology and distribution: Known from northern Central America and East Asia, associated with species of the family Fagaceae and the family Pinaceae .

Currently known species: Retiboletus brevibasidiatus Raspé & Chuankid (2021: 297) , R. flavoniger (Halling, G.M. Muell. & L.D. Gómez) Binder & Halling (2002: 30) , R. kauffmanii , R. ornatipes , R. retipes , R. sinensis N.K. Zeng & Zhu L. Yang (2016: 363).