Suillus plorans (Rolland) Kuntze, Revis.

Palamarchuk, Marina A., Kirillov, Dmitry V. & Shadrin, Dmitry M., 2021, Morphology and molecular data of the species of Suillus (Suillaceae, Boletales) associated with Pinus sibirica at the European northeast of Russia, Phytotaxa 490 (1), pp. 18-34 : 29-30

Suillus plorans (Rolland) Kuntze, Revis. gen. pl. (Leipzig) 3 (3): 535 (1898)

subsp. plorans ( Fig. 4 c, d )

Pileus 30–60 mm in diam., convex, then expended, surface innately radially fibrillose, soon glabrous, sticky to viscid, yellow-brown or brownish-yellow. Tubes and pores brownish-yellow, yellowish-brown and then brown, adnate. Hymenophore of young specimens is covered by white drops of liquid. Stipe 30–100 × 12–15 mm, cylindrical or tapering below, pale-yellow, yellowish with brown, comma-shaped glandular dots. Flesh white, slightly yellowish in the stipe, slightly orange at the base. Taste mild, smell tarry.

Basidia 19–27 × 6.5–7.5 μm, cylindrical, narrow-clavate, 4-spores. Basidiospores 8.5–10.5 × 3.3–4.5 μm, Q = 2.0–2.9, fusiform, yellowish-brown. Cystidia (cheilo-, pleuro- and caulocystidia) 29–68 × 5–14 μm, cylindrical, clavate or slightly swollen at the apex, hyaline or with dark-brown content, fasciculate. Pileipellis ixotrichoderm, consisting of more or less intertwined hyphae of 4–12 μm width, immersed in gelatinous substance. Hyphae lightyellow-brown, sometimes with incrustation.Among common light-yellow-brownish hyphae present single apical sites with dark-brown content. Clamp connections absent in all tissues.

Ecology and distribution. The species forms ectomycorrhizae with Pinus sibirica and P. cembra , occurs in Europe, in Alps and Tatras ( Munoz 2005; Ronikier et al. 2002; Galli 2007). In Russia, according to Vasylkov (1971), it occurs throughout all Asian part, where the arrays of forests with P. sibiricus are common. In more recent publications, this species was reported for Eastern ( Nezdojminogo 1969; Kutafjeva 1989; Petrov 1991) and Western Siberia ( Zvyagina 2008), Northern Urals ( Perevedentseva 2008) and Far East ( Sazanova 2009).

Collection examined. RUSSIA, Troitsko-Pechorsky district, Pechoro-Ilychsky Nature Reserve, 12 km upstream the Pechora River from settlement Yaksha, 61°47’31.3”N, 57°03’21.2”E, the edge of mire, spruce forests with Pinus sylvestris and Pinus sibirica , 16 Aug. 2015, col. M. Palamarchuk, SYKOf 2666. Vuktyl district, “Yugyd va” National Park, basin of the Schugor River, Nizhnie Vorota, left bank, 2 km upstream, 64°12’45.1”N, 57°59’45.3”E, spruce green moss forest with Pinus sibirica , 10 Aug. 2016, col. M. Palamarchuk, SYKOf 2594.

Note. In the field, S. plorans can be easily confused with S. punctipes . These species can be distinguished only by the combination of characteristics. The basidiomata of S. plorans is predominantly yellow color; the glandular dots on the stem are brown, rarely watery-milky. After analysis of all Suillus specimens stored in SYKOf, we found that the most distinguished character, separating these species, is the occurrence in pileipellis of S. plorans of hyphae with dark-brown content, whereas S. punctipes lack them.All other characteristics, which are commonly used for separating these species (color of mycelium, smell), overlap and are not always clearly definable and so, cannot be used as diagnostic.

subsp. cyanescens Singer, Pilze Mitteleuropas (Stuttgart) 5 (1): 81 (1965) ( Fig. 4 e, f )

Pileus 30–60 mm in diam., convex, then expended, surface innately radially fibrillose, soon glabrous, sticky to viscid, yellow-brown, brownish-yellow or brown. Tubes and pores brownish-yellow, yellowish-brown and then brown, adnate. Hymenophore of young specimens is covered by white drops of liquid. Stipe 70–100 × 12–15 mm, cylindrical or tapering below, pale-yellow, yellowish with brown, comma-shaped glandular dots. Flesh white, slightly yellowish in the stipe, slightly orange at the base, bluing when cut. Taste mild, smell tarry.

Basidia 19–28 × 6.5–7.5 μm, cylindrical, narrow-clavate, 4-spores. Basidiospores 8–10(11) × 3.3–4.5 μm, Q = 2–3, fusiform, yellowish-brown. Cystidia (cheilo-, pleuro- and caulocystidia) 30–68 × 7–14 μm, cylindrical, clavate or slightly swollen at the apex, hyaline or with dark-brown content, fasciculate. Pileipellis ixotrichoderm, consisting of more or less intertwined light-yellow-brownish hyphae of 4–12 μm width, immersed in gelatinous substance, аmong common hyphae present single apical sites with dark-brown content. Clamp connections absent in all tissues.

Ecology and distribution. The subspecies forms ectomycorrhizae with Pinus sibiricus and is known only from Russia. It was found in Altai, where was first described ( Singer 1965), in Magadan ( Sazanova 2009) and Urals.

Collection examined. RUSSIA, Troitsko-Pechorsky district , Yaksha-Troitsko-Pechorsk road, 62°17’23.3”N, 56°36’15.6”E, mixed sphagnous forest with Pinus sibirica , 24 Aug. 2017, col. M. Palamarchuk, SYKOf 3003 ; ibid., about 5 km from the settlement Komsomolsk , 62°10’29.3”N, 56°36’5.7”E, mixed sphagnous forest with Pinus sibirica , 26 Aug. 2017, col. M. Palamarchuk, SYKOf 3004, 3005, 3006 .

Note. Suillus plorans subsp. cyanescens was described by Singer in 1965 based on materials from Altai. This subspecies is differed from the type variant by the turning bluing flesh when cut. The hyphae with dark-brown content in pileipellis more numerous than in S. plorans subsp. plorans . From S. punctipes it differs by the turning bluish flesh and presents dark-brown hyphae in pileipellis. Suillus variegatus (Sw.) Richon & Roze (1888: 178) is also very similar but differs by distinctly tomentose and dry pileus, lack glandular dots on stem and habitat with Pinus sylvestris .

Figures

FIGURE 4. Basidiocarps and elements of pileipellis. a, b Suillus punctipes (SYKOf 2598). c, d Suillus plorans (SYKOf 2666). e, f Suillus plorans ssp. cyanescens (SYKOf 3006). Scale bars a, c, e—2 сm; b, d, f—50 μm. Images: Marina Palamarchuk.