Tylocinum Y.C. Li & Zhu L. Yang, in Wu et al., Fungal Diversity 81: 100 (2016)
Etymology: Named because of its phenotypic similarity to the genus Tylopilus and Leccinum.
Diagnosis: This genus differs from all other genera of Boletaceae in its dark scabrous stipe surface, white to pallid, unchanging context in pileus and stipe, white to pallid hymenophore, trichodermium pileipellis and smooth basidiospores.
Basidioma stipitate-pileate with tubular hymenophore. Pileus hemispherical or applanate; surface densely covered with granular or tomentose squamules, dry; context soft when mature, white to pallid, without discoloration when injured. Hymenophore depressed around apex of stipe; hymenophoral surface white to pallid or pinkish when young, and becoming pink to grayish pink when mature; pores relatively wide up to 1.5 mm, angular; tubes concolorous with hymenophoral surface, color unchanging when injured. Stipe central, concolorous with pileus or much deeper in color than the pileus; surface with concolorous verrucose or granular like squamules; basal mycelium pallid. Basidiospores subfusiform smooth (under SEM). Pileipellis a trichodermium, composed of hyphae with 3–5 concatenated cells. Pleuro- and cheilocystidia fusiform to subfusiform often with a sharp apex and a long pedicel. Clamp connections absent.
Index Fungorum number: IF818492
Type species: Tylocinum griseolum Yan C. Li & Zhu L. Yang 2016, in Wu et al., Fungal Diversity 81: 100 (2016)
Notes: The tomentose pileus and soft pileal context in Tylocinum are shared by the species in Xerocomus Quél., but the species in Xerocomus have a yellow to brownish yellow hymenophore and some bluish discoloration when cut. The white to dirty white hymenophore is similar to that of Tylopilus when young, but the verrucose stipe surface is very similar to the species in Leccinum Gray. Phylogenetically, it forms a unique clade in Boletaceae, and this, together with its peculiar morphological characters, is sufficient to suggest a new genus. Only a single species in this genus is known.
Wu G; Li YC; Zhu XT; Zhao K; Han LH; Cui YY; Li F; Xu JP; Yang ZL. 2016. One hundred noteworthy boletes from China. Fungal Diversity. 81:25-188