Suillus flavopunctipes R. Zhang, X. F. Shi, G. M. Mueller & 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 flavopunctipes R. Zhang, X. F. Shi, G. M. Mueller & P. G. Liu sp. nov.

Figs 6 , 7

Etymology.

The epithet refers to the yellow (flavo-) glandular dots (- punctipes) found on the stipe in young sporophores.

Diagnosis.

Suillus flavopunctipes is in the Suillus granulatus morphological complex. This species can easily be differentiated from S. granulatus and S. longiflavopunctipes by its host association with Pinus yunnanensis and P. massoniana in southern China.

Typification.

China: • Yunnan Province, Dali City, Miao-pu hill (25°34'07.32"N, 100°12'20.87"E, alt. 2208 m), 20 August 2012, Rui Zhang RZ 08201207 (holotype HKAS 91433 ) .

Morphology.

Pileus develops from hemispherical to convex or broadly convex, 1–10 cm diameter, surface viscid to glutinous in young or when moist, glabrous, all white or with a brown glutinous layer when young, developing brown (6 D 5 to 6 F 7) patches or streaks above the yellow background (4 A 5, 4 A 6) due to deposition of basidiospores from overlaying sporophores which are captured by the glutinous layer which becomes dried out. Hymenophore adnate to subdecurrent, yellow (3 A 5), surface covered with yellowish milky droplets when young, dotted with brownish dots in age. Does not change color when bruised. Tube mouths small, 1 to 3 per mm, angular. Tubes 0.5–5 mm deep, concolorous with pore surface. Stipe 1.5–6 × 0.5–2.0 cm, cylindrical or tapering downwards, solid, lacking annulus, background color pallid when young, becoming yellowish in apex. Covered with connected glandular dots that form streaks, glandular dots change from yellow (3 A 4) to cinnamon brown (6 E 5–6 E 7) at maturity. Context yellowish white to yellow (3 A 3, 3 A 4) in both pileus and stipe. Does not change color when exposed. Spore print dark cinnamon brown (6 F 5–6 F 7), usually in mass. Odor and taste pleasant smell, taste indistinctive.

Basidiospores [40 / 2 / 2] 8.0–9.5 × 3.0–4.0 μm, Q = (2.00) 2.29–2.83 (3.17), Q sd = 2.49 ± 0.24, 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, 15.0–20.0 × 5.0–6.0 μm, hyaline yellow in KOH, tawny ochraceous in Melzer’s. Hymenophoral trama divergent, wrinkled, thin-walled, hyaline and 5–11 (- 16) μm. Pleuro- and cheilocystidia in fascicles, abundant, clavate, up to 70 μm long, contents brown or hyaline, surrounded by brown amorphous material in KOH. Pileipellis encrusted by tiny hyaline or ochraceous granules, hyphae densely distributed as if interwoven in yellowish glue in KOH, 3–7 (- 10) μm. Stipitipellis covered by patches of brown amorphous pigment, composed of interwoven hyphae about 3–9 μm wide. Caulocystidia abundant over the stipe, morphologically similar with pleuro- and cheilocystidia, base surrounded by brown pigment, up to 100 μm. 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.

Gregarious, in association with Pinus yunnanensis and P. massoniana .

Known distribution.

Mainly distributed in southern China, extending north to Henan Province along with P. massoniana .

Specimens examined.

China: • Yunnan Province, Baoshan City, Long-yang, Banqiao town, Qingshui village (alt. 1800 m), 20 August 2009, Gang Wu, GangWu 98 ( HKAS 57630 ) ; China: • Guangdong Province, Lecang Xian, Jiufeng town, Shi Er Du Shui conservative region , 15 September 2011, Xiaofei Shi, Shi 961 ( HKAS 71974 ) ; China: • Henan Province, Nanyang City, Nei Xiang County, Qili Ping pine forest (alt. 720 m), 7 August 2010, Xiaofei Shi, Shi 440 ( HKAS 63242 ) ; China: • Hubei Province, Shiyan City, Fang Xian, Xi Song town, Xi Ping village (alt. 1200 m), 31 July 2011, Xiaofei Shi, Shi 762 ( HKAS 71892 ) ; China: • Fujian Province, Wuyi Shan City, Long Jing Mountain (alt. 300 m), 4 September 2011, Xiaofei Shi, Shi 883 ( HKAS 71943 ) .

GenBank.

ITS = KX 342861 ; LSU = KU 721336 ; TEFα- 1 = KU 721624 ; RPB 1 = KU 852282 ; RPB 2 = KU 852298 .

Notes.

See above for comparisons of this species with Suillus aenoplacidus . Within the Suillus granulatus complex, this species can easily be differentiated from S. granulatus and S. longiflavopunctipes by its host association and geographic range. Suillus flavopunctipes is a southern China species associated with Pinus yunnanensis and P. massoniana . Morphological characters, including color variations and stipe length, are not stable across large collections and can be affected by growing conditions. For molecular studies, the ITS phylogeny alone can resolve the three species in the Suillus granulatus complex with high support.

Figures

Figure 6. Basidiomata of Suillus flavopunctipes (holotype, HKAS 91433). Scale bar: 5 cm.

Figure 7. Suillus flavopunctipes (holotype, HKAS 91433). a Basidiospores; b. Cheilocystidia; c. Hymenium with basidia; d. Pileipellis (mature specimens). Scale bars: 5 μm (a); 20 μm (b – d).