Hortiboletus hershenzoniae Biketova & Wasser 2025, sp. nov.

Hortiboletus hershenzoniae Biketova & Wasser sp. nov. Figs 3 c, d, 8, 13, 14, 15 Diagnosis. Basidiomes pileate-stipitate, xerocomoid, epigeal, small to medium-small-sized. Young basidiomes usually have a red pileus and yellow stipe, but with age, the colour of the pileus can fade to various tints of brown or greyish-brown and the stipe surface develops a dark-red tint (red scales or fibrils on a yellow background). Pileus up to 10 cm in diam., dry, finely tomentose, sometimes alveolate-rugose or with small cracks. Tubes adnate to slightly decurrent, initially pale yellow to lemon yellow and becoming olivaceous-brown with age, slightly bluing when cut. Pores angular, uneven and denticulate in mature basidiomes, concolourous with tubes, only weakly bluing when bruised. Stipe up to 12 cm long, central or slightly off-centre, usually slender especially in young basidiomes, cylindrical, curved, somewhat tapering towards the base and slightly rooting. Context firm to soft in the pileus, fibrous and brittle in the stipe; pale yellow to lemon yellow, sometimes from pale pink to vinaceous underneath the pileus surface in old basidiomes, usually with minute dots of orange-red or vermilion-red pigment in the stipe base (sometimes dots are absent in young basidiomes); only erratically and slightly bluing when exposed to air. Basidiospores 11.4–13.9 × 6.0–6.6 µm, Qm = 2.02 ± 0.17, broadly elliptical to broadly fusiform, smooth. Pileipellis a palisadoderm, of long, parallel, smooth or sometimes encrusted hyphae; terminal elements 20.0–48.2 × 9.0–13.8 μm, mostly cylindrical and somewhat tapering towards the apex. Etymology. Named in honour of the late Zehara Avizohar-Hershenzon, who was one of the pioneers of the mycological science and investigations of macrofungi in Israel. Holotype (MTB 10011371). ISRAEL • Sharon Plain: Zikhron Ya’akov, 32°34'28"N, 34°58'33"E, under Quercus calliprinos, 01. 12. 2012, leg. R. Kuznetsov, K-M 001435594 (AB B 12-071 – collector’s number), GenBank: ITS + LSU – PV 030528, tef 1 - α – PV 088300, and rpb 2 – PV 088311. Description. Basidiomes pileate-stipitate, xerocomoid, epigeal, small to medium-small-sized. Sometimes basidiomes grow fused together, forming one common pileus originating from two different stipes. Ontogenetic development gymnocarpic. Pileus 1.9–10 cm diam., initially nearly hemispherical, then convex, applanate to almost flattened, slightly depressed at centre, sometimes irregularly shaped, dry, finely tomentose, sometimes alveolate-rugose or with fine or coarse cracks especially in dry weather, with cream or yellowish (basidiomes with red pileus) or also vinaceous-red (basidiomes with brownish pileus) context in the cracks; pileus surface very variable in colour, initially with different tints of red (blood red, cherry red, rose red, vinaceous-red: BFF 41; OAC 600–605, 607, 621–623) and then usually slowly fading to various tints of brown or greyish-brown and ochraceous (hazel, clay buff, sepia, milky coffee, cigar brown, greyish-ochraceous: BFF 16, 17, 26 - 8, 32; OAC 770, 771, 778, 736, 743, 745), especially in dry weather; cap margin slightly inrolled in young basidiomes and then straight, acute, sometimes obtuse gibbous-corrugate, somewhat (sometimes significantly) paler than the central part of the pileus in young basidiomes. Tubes up to 15 mm long, at first adnate, later emarginate or slightly decurrent with a tooth, initially straw yellow, lemon yellow or greenish-yellow (BFF 50, 54, 57, 64; OAC 1, 3, 896, 897), later greenish-yellow, citrine olivaceous to olive brown (OAC 801, 817, 832, 838, 894); slightly bluing when injured. Pores angular, uneven and denticulate in mature basidiomes, pale yellow, lemon or greenish-yellow (BFF 54, 57, 64; OAC 3, 856, 894, 896, 897) in young basidiomes and citrine olivaceous to olive brown with rusty tint (OAC 804, 848, 825, 839, 838, 785) with age, only weakly bluing when bruised. Stipe 4–11.5 × 0.7–3.7 cm, versiform, central or slightly off-centre, usually slender especially in young basidiomes, cylindrical, curved, somewhat tapering towards the base and slightly rooting, dry, initially smooth or slightly fibrillose and straw or lemon yellow throughout (BFF 50; OAC 1, 3, 853, 855, 856, 898) in wet weather, then becoming ornamented with vinaceous-red and brownish-red scales or fibrils (BFF 17, 19, 20; OAC 657, 635, 601, 602, 622) in the upper or middle part of the stipe and sometimes towards the base especially in dry conditions. Basal mycelium yellow or dirty yellow (OAC 1, 3-5, 853, 856, 847). Context firm to soft in the pileus, fibrous and brittle in the stipe; pale yellow, sulphur yellow to lemon yellow (BFF 55; OAC 1, 858), slowly fading on drying especially in the pileus, sometimes from pale pink to vinaceous (BFF 76, OAC 578, 599, 611) underneath the cuticle in old basidiomes, usually with minute dots of red-orange or orange-red (OAC 630, 649, 677) pigment in the stipe base that is mostly visible only under a stereomicroscope and sometimes absent in young basidiomes; sometimes only slightly bluing in the pileus and / or in the upper and middle part of the stipe (in wet weather) when exposed to air. Spore print olive brown (OAC 831, 832). Odour inconspicuous. Taste mild. Macrochemical spot-test reactions: Melzer’s reagent: a weak fleeting-amyloid reaction on the hymenophoral trama and on the stipe and pileus context of fresh and dry basidiomes; 25 % NH 4 OH: fading of pinkish pigment of the pileus context under cuticle; 10 % FeSO 4: olivaceous (BFF 62; OAC 866, 868, 832, 882) to bluish-grey on the context in the stipe base and pale olivaceous (OAC 850) to olivaceous-black (OAC 36, 37) on the pileus context; 10 % H 2 SO 4: sienna to light yellow ochre and (OAC 706, 707, 810–813) on pileus surface, yellow ochre (OAC 810–812) on pores, and olive-ochraceus to yellow ochre (OAC 803, 811, 818, 825) on the stipe context. Basidiospores [336 / 10 / 10] (10.8 –) 12.4 ± 0.9 (– 13.9) × (5.5 –) 6.2 ± 0.3 (– 6.6) µm, Qm = (1.90 –) 2.01 ± 0.08 (– 2.22), Vm = 251 ± 40 µm 3, broadly elliptical to broadly fusiform, smooth, with a weak suprahilar depression in profile, yellowish ochraceous, with 1–3 large guttules when mature. Basidia 28–42 × 9–13 μm, generally four-spored, clavate, hyaline to yellowish, guttulate, without basal clamp. Basidia [51 / 2 / 2] (32.5 –) 48.4 ± 8.2 (– 74.0) × (11.8 –) 14.2 ± 1.9 (– 19.5) μm, subclavate to clavate, predominantly 4 - spored, sterigmata (2.5 –) 3.2 ± 1.7 (– 6.7) μm long, hyaline to yellowish in 5 % KOH and containing concolourous oil guttules, without basal clamps; basidioles subcylindrical to faintly clavate, smaller than basidia. Cheilocystidia [11 / 2 / 2] (45.0 –) 52.7 ± 6.3 (– 65.0) × (8.2 –) 12.4 ± 2.9 (– 16.2) μm, slender, ventricose-fusiform, often with elongated neck, with rounded tip, smooth, mostly hyaline to pale yellowish, some with intracellular yellowish oil content, in water and 5 % KOH. Pleurocystidia [30 / 2 / 2] (38.0 –) 56.5 ± 8.1 (– 70.0) × (10.0 –) 13.6 ± 2.2 (– 19.5) μm, slender, ventricose-fusiform, often with elongated neck, with rounded tip, smooth, mostly hyaline to pale yellowish, some with intracellular yellowish oil content, in water and 5 % KOH. Pseudocystidia not observed. Hymenophoral trama bilaterally divergent, intermediate between the “ Phylloporus - type ” and the “ Boletus - type ”: lateral strata consisting of poorly divergent, tightly arranged, non-gelatinous hyphae almost touching each other, hyaline to very pale yellow in water and 5 % KOH; mediostratum consisting of tightly adpressed, non-gelatinous, parallel running hyphae; in Congo red, the mediostratum is slightly darker than the lateral strata. Pileipellis a palisadoderm of long, parallel, septate, smooth or encrusted (by granular pigment) hyphae; terminal elements [322 / 10 / 10] (25.2 –) 32.6 ± 5.9 (– 44.2) × (7.3 –) 10.9 ± 2.1 (– 13.9) μm, Qm = (2.32 –) 3.03 ± 0.43 (– 3.61), encrusted, mostly cylindrical and somewhat tapering towards the apex, obtusely triangular, acorn-shaped. Stipitipellis consisting of slender, subparallel, smooth walled, round tip, pale-yellow in 5 % KOH hyphae, (3.0 –) 3.5–4.5 (– 6.5) μm broad. Bundles of a caulohymenium, constituted of clavate caulobasidioles (23.0 –) 31.0–35.2 (– 42.5) × (8.0 –) 9.3–12.1 (– 14.5) μm, hyaline to pale yellow in 5 % KOH are observed in the upper part of the stipe; fertile caulobasidia not observed. Confused, intermixed, sometimes ramified 4.4–6.0 μm hyphae from which caulobasidioles arise were observed, not constituting a true lateral stratum. Stipe trama consisting of parallel running, (5.5 –) 6.7–7.1 (– 8.0) μm broad, sometimes restricted to septa hyphae, hyaline in 5 % KOH, inamyloid; infrequent, versiform thromboplerous hyphae are observed here and there. Clamp connections absent in all tissues. Ecology and phenology. Solitary, in small groups, or caespitose, in Mediterranean thermophilous forests, growing with Quercus calliprinos (Sleiman et al. (2021), as H. engelii, GP; pers. observ., GP), possibly also with Q. ithaburensis on calcareous soil, common in its habitat. There are some molecularly unconfirmed data referring to a putative association with Pinus halepensis. The main fruiting period starts after the first prolonged and heavy rains and goes from late October to December, sometimes continuing until the last rains in April. Known distribution (see Fig. 5 b). So far known from Israel (this study, GP) and Lebanon (Sleiman et al. (2021), as H. engelii, GP). It likely grows in other countries of the eastern Mediterranean region. Additional examined material. ISRAEL • Carmel Mount: Mt. Carmel National Park, Nahal Oren valley, Henyon Ha’Agam, 32°43'26"N, 35°00'55"E, 260 m, under Q. calliprinos, four from young to mature basidiomes, 13. 11. 2012, leg. Y. Cherniavsky & O. Godorova, det. A. Biketova, K-M 001435678 (AB B 12-024, GP); • the same locality, two aged basidiomes, 17. 11. 2012, leg. O. Godorova & A. Biketova, det. A. Biketova, K-M 00143568