Suillus longiflavopunctipes R. Zhang, X. F. Shi, G. M. Mueller and P. G. Liu, 2025

Shi, Xiaofei, Zhang, Shiru, Mueller, Gregory M., Liu, Peigui, Yu, Fuqiang & Senanayake, Indunil C., 2025, A subgeneric revision of the genus Suillus (Suillaceae, Boletales) and novel taxa from Eastern Asia based on morphology and multigene phylogenies, IMA Fungus 16, pp. e 144260-e 144260 : e144260-

Suillus longiflavopunctipes R. Zhang, X. F. Shi, G. M. Mueller and P. G. Liu sp. nov.

Figs 8 , 9

Etymology.

“ longi -” means that the stipe of young sporophore is comparatively longer than that of S. flavopunctipes .

Diagnosis.

Suillus longiflavopunctipes young sporocarps have comparatively longer stipes than other similar species in the S. granulatus morphological complex. This species is associated with Pinus densiflora and P. thunbergii , and one collection is with P. sylvestris var. sylvestriformis .

Typification.

China: • Shandong Province, Linyi City, Pingyi town, Dianzi Plantation (35°32'22.14"N, 117°55'12.42"E, alt. 250 m), 24 August 2011, Xiaofei Shi, Shi 828 (holotype, HKAS 71922 ) .

GenBank.

ITS = KU 721235 ; LSU = KU 721340 ; RPB 1 = KU 852195 ; RPB 2 = KU 852296 .

Morphology.

Pileus develops from hemispherical to convex or broadly convex, 2–9 cm diameter, surface viscid to glutinous, glabrous, younger ones all white, or the glutinous layer in cinnamon brown color patches (5 B 4, 5 C 5). Color reddish brown without color patches in age (6 D 5–6 F 5). Hymenophore adnate to subdecurrent, yellow (3 A 5), with milky white droplets when young, dotted with brownish dots when age. Do not change color when bruised. Pores 1 to 2 per mm, smaller towards margin, angular. Tubes 2–3 mm deep, concolorous with pore surface. Stipe 5–7 × 0.8–1.5 cm, cylindrical or tapering downwards, solid, no annulus, background color pallid in young, become yellowish, darker yellow in apex when age. Covered all over with big and almost linked glandular dots, glandular dots change from yellow (3 A 4) to vinaceous brown (5 C 4–5 E 4) when age. Context yellowish white to yellow (3 A 3, 3 A 4) in pileus and stipe. Do not change color when exposed. Spore print cinnamon brown (5 B 4, 5 C 5). Odor and taste pleasant smell, taste indistinctive.

Basidiospores [80 / 2 / 2] (8.0) 8.5–10.0 × 3.5–4.0 μm, Q = 2.25–2.57 (2.71), Q sd = 2.38 ± 0.12, smooth, oblong in face view, narrowly inequilateral with a hilar appendage in profile view, hyaline yellow or brown in KOH, tawny ochraceous in Melzer’s. Basidia 4 - spored, clavate, bulbous at top, 22.0–27.0 × 6.0–7.0 μm, yellowish in KOH, tawny ochraceous in Melzer’s. Hymenophoral trama divergent, wrinkled, thin-walled, hyaline and mostly 5–11 μm, up to 16 μm. Pleuro - and cheilo cystidia in fascicles, abundant, clavate, up to 70 μm long, content brown or hyaline, surrounded by brown amorphous materials in KOH. Caulocystidia abundant all over the stipe, morphologically similar with pleuro- and cheilocystidia, basal surrounded by brown pigments, up to 100 μm. Pileipellis encrusted by tiny hyaline or ochraceous granules, hyphae densely distributed as if interwoven in yellowish glue in KOH, most 3–7 μm, up to 10 μm wide. Stipitipellis covered by profuse brown amorphous pigments, composed of interwoven hyphae, about 3–9 μm wide, most contain brown pigments. Context trama hyaline, smooth, thin-walled, interwoven, similar in pileus and stipe, mostly 3–30 μm, up to 40 μm wide at stipe base. Clamp connections absent.

Habitat.

Solitary to scattered, in association with Pinus densiflora and P. thunbergii , and one collection is with P. sylvestris var. sylvestriformis .

Known distribution.

Natural range is in northeastern China, Korea and Japan.

Specimens examined.

China: • Jilin Province, Antu Town, Changbai Mountain, Junshi Bu yard (alt. 748 m), 7 August 2010, Xiaofei Shi, Shi 445 ( HKAS 63209 ) ; China: • Shandong Province, Qingdao City, Lao Mountain (alt. 300 m), 18 August 2011, Xiaofei Shi, Shi 812 ; China: • Shandong Province, Linqu town, Jiushan village, Black pine forest park (alt. 200 m), 23 August 2011, Xiaofei Shi, Shi 824 ( HKAS 71918 ) ; China: • Shandong Province, Linyi City, Pingyi town, Dianzi plantation (alt. 450 m), 24 August 2011, Xiaofei Shi, Shi 829 ( HKAS 71923 ) ; China: • Shandong Province, Linyi City, Pingyi town, Dianzi plantation (alt. 450 m), 24 August 2011, Xiaofei Shi, Shi 830 ( HKAS 71924 ) ; China: • Jiansu Province, Lianyungang City, Huaguo Mountain (alt. 100 m), 27 August 2011, Xiaofei Shi, Shi 837 ( HKAS 71925 ) ; China: • Jiangsu Province, Lianyungang City, Huaguo mountain , 27 August 2011, Xiaofei Shi, Shi 838 ( HKAS 71926 ) .

Notes.

Differences of this species with Suillus aenoplacidus and S. flavopunctipes are in above commentaries. But it remains confusing for the delimitations of Suillus longiflavopunctipes and S. granulatus , the latter distributes from Europe to northeastern China. The two species have overlapped geographic ranges and one shared host P. sylvestris var. sylvestriformis . Though S. granulatus sensu stricto is not found growing with Pinus densiflora and P. thunbergii , further studies are required to confirm host associations of the two species. Morphological identifications are not easy to apply for the S. granulatus complex, but molecular phylogenies, even ITS phylogeny alone, can separate these species.

Figures

Figure 8. Basidiomata of Suillus longiflavopunctipes (holotype, HKAS 71922). a Mature basidiomata. b Young basidiomata. Scale bar: 5 cm.

Figure 9. Suillus longiflavopunctipes (holotype, HKAS 71922). a Basidiospores; b Cheilocystidia; c Hymenium with basidia; d Pileipellis (mature specimens). Scale bars: 5 μm (a); 20 μm (b – d).