Hortiboletus kohistanensis, Naseer, Arooj, Sarwar, Samina, Khalid, Abdul Nasir, Healy, Rosanne & Smith, Matthew E., 2019

Naseer, Arooj, Sarwar, Samina, Khalid, Abdul Nasir, Healy, Rosanne & Smith, Matthew E., 2019, Hortiboletus kohistanensis (Boletaceae), a new bolete species from temperate and subalpine oak forests of Pakistan, Phytotaxa 388 (3), pp. 239-246 : 242-244

publication ID	https://doi.org/ 10.11646/phytotaxa.388.3.3
persistent identifier	https://treatment.plazi.org/id/203B87F1-FFB9-3129-6485-F8B971CCFF3C
treatment provided by	Felipe
scientific name	Hortiboletus kohistanensis
status	sp. nov.

Treatment

Hortiboletus kohistanensis View in CoL A. Naseer., S. Sarwar & A.N. Khalid, sp. nov. Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3

MycoBank no.:—MB 824504.

Diagnosis: Pileus convex to plano-convex, reddish brown to yellow, areolate, centrally depressed. Hymenophore staining brown upon bruising. Stipe whitish at the base as compared to the closely related species H. indorubellus , which has a non-areolate pileus surface, yellowish stipe base and the entire stipe is more longitudinally fibrillose. Basidiospores ellipsoid, non-truncate; pilepellis a palisadoderm. Phylogenetically nested in the H. rubellus clade.

Holotype:— PAKISTAN. Khyber Pakhtunkhwa Province: Swat Valley, Toa, under Quercus incana , 15 July , 2015, A. Naseer and A. N. Khalid , LAH35327 About LAH ; GenBank MG988192 (ITS); MG988187 ( LSU). Gene sequences Isotype: MG988193 (ITS).

Etymology:— ‘ kohistanensis ’ refers to the ‘Kohistan’ District of Hazara Division. Swat Kohistan is the type locality. This is a valley in the Khyber Pakhtunkhwa Province of Pakistan.

Description:— Basidiomata small to medium-sized. Pileus 2.5–7.5 cm in diameter, broadly convex when young, becoming plano-convex, centrally depressed, brownish (9.4YR 3.7/4.1) when young, reddish brown (10Y 7.2/4.8) at maturity, velvety, rimose-areolate at maturity, margin entire, smooth, brown (9.4YR 3.7/4.1) to reddish (5.3YR 3.4/7.3); Pileitrama yellowish white gradually staining brown upon exposure, margin entire, smooth, brown (9.4YR 3.7/4.1) to reddish (5.3YR 3.4/7.3). Hymenium depressed near stipe, light yellow when young, becoming gradually dark yellow (4.1Y 4.1/5.3) at maturity, gradually staining brown (9.6Y 1.7/2.5) upon bruising; Pores circular to angular to irregular, 2–3 pores per mm; Tubes 5–7 mm deep, tubes concolorous with pores. Stipe 4–10.5 cm long, 0.4–1 cm thick, at maturity 1.5 cm thick on average, central, solid, cylindrical, with slightly swollen base, curved when young, gradually straightening with maturity, whitish at the base, olive brown to yellowish brown to yellowish (3.6Y 5.2/4.9) towards apex when young, gradually becoming reddish brown (10Y 7.2/4.8) at maturity, longitudinally fibrillose in the upper half, smooth elsewhere. Odor mild, taste not confirmed.

Basidiospores (7.7–) 9–11 × (3.8–) 4–5.3 μm, avL × avW = 10.2 × 4.59, avQ = 2.2, yellow in 5% KOH, ellipsoid, apiculate, smooth, guttulate, thick-walled, non-truncate. Basidia 37–54 × 11.5–13 μm, light green in 5% KOH, guttulate, 4-spored, sterigmata up to 3.5–4 μm long, thin-walled, clavate to subclavate. Hymenial cystidia 39–68 × 10–12 μm, light brown in 5% KOH, subclavate to fusiform to fusoid-ventricose, oil contents visible. Pileipellis a palisadoderm composed of chains of erect branched, cylindrical cells, 14–62 × 12–25 μm, yellowish brown in 5% KOH, septate, with a scattered epiparietal encrusting brown pigment, thick-walled. Stipitipellis hyphae 39–75 × 5–13 μm, light yellow in 5% KOH, septate, branched, thin-walled. Caulocystidia 28–50 × 6–12 μm, fusiform, light brown. Habitat and distribution:—Swat, Toa, 2800 m a.s.l, under the canopy of Quercus incana .

Additional specimen examined:— PAKISTAN. Khyber Pakhtunkhwa Province: Swat Valley, Toa , Q. incana , 15 July 2015, A. Naseer and A. N. Khalid, AST22 About AST ( LAH35285 About LAH ; ITS sequence MG988193 ) .

Molecular phylogeny

ITS sequences showed maximum similarity with “ Xerocomus sp. ” KJ609174 from Mt. Oseo on the Korean Peninsula. Although it is labeled as a Xerocomus in GenBank, our phylogeny shows that this is a species of Hortiboletus and we label it accordingly in Figure 4 View FIGURE 4 . The LSU sequence from the holotype specimen of H. kohistanensis was most similar to H. amygdalinus Xue T. Zhu & Zhu L. Yang (2016: 81) from Yunnan, China ( Wu et al. 2016). To avoid taxonomic confusion, the name for the newly described species has been listed with respective GenBank accession numbers in the phylogenetic trees ( Figs. 4 View FIGURE 4 , 5 View FIGURE 5 ). The ITS analysis included 23 nucleotide sequences with a total of 907 nucleotide characters. Of these, 582 were conservative and 321 were variable. In the ITS phylogram, the sequences from basidiomata generated during this study fall into the Hortiboletus clade. They form a sister group with H. indorubellus K. Das, D. Chakr., Baghela, S.K. Singh & Dentinger (2016: 108) with strong bootstrap support and are resolved as distinct species ( Fig. 4 View FIGURE 4 ). The LSU analysis included 29 sequences with a total of 878 nucleotide characters. Of these 732 were conservative and 140 were variable ( Fig. 5 View FIGURE 5 ). Our sequence forms a strongly supported clade with sequences related to the H. rubellus (Krombh.) Simonini, Vizzini & Gelardi , in Vizzini, Index Fungorum (2015: 244) complex.