Микология и фитопатология, 2019, T. 53, № 6, стр. 325-341

Telamonioid species

The subgenus Telamonia sensu Brandrud et al. (1990–2018) and Niskanen et al. (2012), now referable as “telamonioid species” consists of mainly small to medium-sized species with a hygrophanous pileus (changing colour when water-soaked) (see Brandrud et al. 1990–2018). Many are ochraceous to greyish or reddish brown, and include a number of taxonomic, intricate complexes that hardly can be solved without molecular methods. These are here verified by sequencing data. This group was the dominating in our material, with 25 species recorded in the Altay Nature Reserve (29 species when Gorno-Altaysk included), and included many rare and little known taxa new to this part of Eurasia, especially those found in the mossy-herb-rich Pinus-Betula delta forests.

**Cortinarius adustorimosus Rob. Henry (= C. pseudorubricosus Reumaux) – Kokshi, TEB 154-18 (LE 312101) (Fig 2a).

This species has also been called C. pseudorubricosus, and it is possible that the older name C. procax Melot (1980) covers the same species. This is a large fungus in the sect. Brunnei, when young resembling C. suberi, with an innately fibrillose to marbled pileus, and browning with age, like e.g. C. brunneus (but never so dark). The species has characteristic, very small spores, smaller than e.g. C. suberi. In Altay the species was found in mossy, herb-rich Pinus sylvestris forest on sand-pebble deposits in the Kokshi delta. This species seems to prefer sandy pine forests, and is so far reported from a few places in Fennoscandia (Niskanen et al., 2009) and North America (Niskanen et al., 2013). This is the first report from Russia, Siberia, and apparently also from Asia.

*Cortinarius agathosmus Brandrud, H. Lindstr. et Melot – Kokshi, TEB 223-18 (LE 213080).

This was found once in the mossy Pinus – Betula forest at the Kokshi river delta. The species seems to be a typical boreal taiga species, in northwestern Europe known mainly from Picea forests, but also recorded in (subalpine) Betula forests (Brandrud et al., 1990–2018). It is reported with sequence-verified material from Western Siberia by Vaishlya et al. (2017).

*Cortinarius alborufescens Imler – Kokshi, river delta, TEB 153-18 (LE 315537), TEB 165b-18 (LE 315538) (Fig 2b).

This large and robust species resembles C. laniger and C. solis-occasus, having thick fibrillose veil remnants on pileus, and a thick, almost membranaceous veil girdle at the stipe. However, C. alborufescens differs from the other by its small, amygdaloid spores. The species seems to prefer sandy pine forests, but apparently mainly associated with Betula spp., which can occur here and there in sandy pine forests. In Altay it was found in the pine-birch forest of the sandy-stony delta of Kokshi. This was also collected by Meinhard Moser along Teletskoe Lake in 2001 (bay in SE; collection under the name C. lanigeroides, in Herbarium IBF Ferdinandeum Innsbruck; U. Peintner pers. comm.). In 2018 it was found also in the Tomsk region (pers. obs.), and recently also in the Khanty-Mansiysk region (Filippova, Bulyonkova, 2017), representing the first report of C. alborufescens for Russia and for Asia. However, the report of C. pearsonii from dry Betula forests in the Volga basin by Iwanow and Durandin (1996), very probably refer to the same species. Apart from these records, this species is reported only from (North) Western Europe; from Fennoscandia (Jeppesen et al., 2012, Brandrud, 1990–2018), Scotland (Orton, 1958, as C. pearsonii) and Belgium (Imler, 1955). The species seems to be rare everywhere.

*Cortinarius balaustinus Fr. – Kokshi, TEB 217-18 (LE 315524).

C. balaustinus is with its small, subglobose spores, a characteristic Betula associate, which occurs scattered in boreal coniferous forests with Betula, in northwestern Europe more frequently in subalpine birch woodlands (Brandrud et al., 1990–2018). It is reported from Picea – Abies – Betula forests of Western Siberia by Filippova and Bulyonkova (2017). Altogether, it is now recorded from 11 regions of Russia.

*Cortinarius bivelus (Fr.) Fr. – Kokshi, TEB 159-18 (LE 312098), TEB 215-18 (LE 312067); Baygazan, TEB 192-18 (LE 312091).

C. bivelus was one of the more frequent Betula-associated species at along Teletskoye Lake, found in herb-rich sites, both in the pristine forest slopes of Baygazan, the sand-boulder delta forests of Kokshi and Chelush, as well as on grazed semi-natural sites around the village of Yaylu.

*Cortinarius casimiri (Velen.) Huijsman – Chelush, TEB 17818 (LE 312096); Kokshi, TEB 22818 (LE 312086).

Cortinarius casimiri in traditional morphological concept (sensu Brandrud et al., 1990–2018), is a collective species comprising more small, C. decipiens – C. vernus-like taxa with large spores > 11 um long. We believe that the present, widespread species, with a rather pronounced pink/vinaceous staining stipe base, is the true C. casimiri.

Cortinarius comptulus M.M. Moser – Kokshi, river delta, TEB 224-18 (LE 312085) (Fig. 3a).

This is a small red-brown or grey-brown telamonioid species, with glossy pileus, initially fine fibrillose to somewhat scaly at margin. Many groups of small, anonymously brown telamonioid taxa have been little understood, and their habitat and distribution thus also little known. This applies also to C. comptulus, even though this one is characterized by very small, almost subglobose spores. The species resembles taxa in the C. flexipes group, but differs e.g. on the lack of a pelargonium smell. A few taxa in the C. flexipes group also possess broadly ellipsoid-subglobose spores, but not so small as in C. comptulus. Cortinarius comptulus also resembles C. hemitrichus, but the latter is more strongly white scaly-flocculose on the pileus when young, and has larger, ellipsoid spores. The species is found mainly in moderately rich to calcareous, herb-rich to grassy Picea and Pinus forests (Brandrud et al., 1990–2018; pers. obs.). In Altay, C. comptulus was found in large groups in the sandy near-shore margin of the Kokshi delta, growing under Pinus. Several reports exist of this from Western Siberia (Kudashova et al., 2013; Filippova, Bulyonkova, 2017; Vaishlya et al., 2017).

Cortinarius decipiens (Pers.) Fr. – Kokshi, TEB 163-18 (LE 315532). Gorno-Altaysk, south of Mayma River, TEB 244-18 (LE 312089); TEB 246-18 (LE 315530).

This sequence-verified collection was found in calcareous Betula forest. The species, which here is treated in the sense of Brandrud et al. (1990–2018) pro-bably has rather wide host preferences, but is in northwestern Europe most frequently found under Populus tremula and Salix spp., including alpine habitats.

*Cortinarius diasemospermus Lamoure var. leptospermus H. Lindstr. – Kokshi, TEB 161-18 (LE 295100). Chelush, TEB 173-18 (LE 312099). Bele, TEB 180-18 (LE 315540).

This little known species was found by us both during the Altay expedition as well as the Tomsk mycological workshop prior to the expedition. It seems to preferentially occur in rich deciduous forests, in Altay probably with Betula. Cortinarius diasemospermus s.l. is reported from Western Siberia by Filippova and Bulyonkova (2017).

*Cortinarius disjungendus P. Karst. – Kokshi, river delta, TEB 218-18 (LE 315525), TEB 219-18 (LE 315526). Gorno-Altaysk, south of Mayma River, east of ski-lift, TEB 235-18 (LE 312064); Biryula Village near Mayma River, TEB 249-18 (LE 312068) (Fig. 2c).

Cortinarius disjungendus belongs to a large complex of semi-cryptic species (sect. Disjungendi; Liimatainen et al., 2014b). The complex is characterized by rather large (grey-)brown species, with somewhat grey discolouring stipe context, and also stipe surface, at least when bruised. With these features, the sect. Disjungendi species resembles those of sect. Bovini, but the former are usually distinguished on the slightly large spores, normally being > 6 µm wide (Niskanen et al., 2012). Cortinarius disjungendus is the most frequent species in the complex, but still pretty rare, and associated with Betula. In Altay the species was found in large populations in the most calcareous hotspots of the grazed, semi-open Betula woodlands around Gorno-Altaysk, and appears to be character species for this habitat. But it was found also once under Betula in herb-rich vegetation at the Kokshi delta of Altaiskiy Nature Reserve.

*Cortinarius flabellus (Fr.) Fr. – Kokshi, TEB 164-18 (LE 295101).

This unit is treated here as a collective morpho-species, including non-scaly, strongly pelargonium-smelling variants in the C. flexipes-complex, corresponding to C. flabellus sensu Brandrud et al. (1990–2018). The species is published in several regional lists of Russia.

Cortinarius gentilis (Fr.) Fr. – Kokshi, TEB 162-18 (LE 315515).

This frequent species in the western, boreal taiga regions, was found only once during our Alai expedition. The species is reported from 18 regions of Russia.

Cortinarius hemitrichus (Pers.) Fr. – Kokshi, TEB 225-18 (LE 315523).

The species is a characteristic and very widespread Betula associate, distinguished e.g. on the initially white, flocculose pileus surface. In Altay, it was found on the sandy-gravelly delta at Kokshi, in mixed birch-pine forest. The species is reported from many regions of Russia, and recently with sequence-verified material from Western Siberia by Vaishlya et al (2017).

Cortinarius hinnuleus Fr. coll. – Chelush, TEB 167b-18 (LE 312095); Kokshi, TEB 227-18 (LE 312084).

This is a complex of semi-cryptic species; that is, phylogenetically well-circumscribed taxa with overlapping morphological variation. One of the Altay collections (from Chelush) was sequenced, and corresponds with C. garciae. C. garciae is one of few taxa in the C. hinnuleus-complex/group that seems to occur mainly in boreal coniferous-birch forests. However, since the phylogeny including nomenclature of the group is not settled, we treat this for the time being as C. hinnuleus coll. All the Altay collections were found under Betula. Most of the taxa in this complex in Europe preferentially occur in thermophilous deciduous forests or parks.

*Cortinarius lux-nymphae Melot – Kokshi, TEB 231-18 (LE 312059).

This is another species typical of sandy pine forests, most frequently growing in short pioneer mosses along small tracks or paths. It was first reported from Western Siberia by Filippova and Bulyonkova (2017).

**Cortinarius melitosarx Soop – Kokshi, TEB 229-18 (LE 312090).

This rather anonymous species is often difficult to identify in the field, due to similarity with other taxa, such as the strongly polymorphic C. biformis. However, C. melitosarx is distinguished from C. biformis in the more vivid ochre yellowish staining stipe and context, and the lack of bluish (-grey) tinges in young stages. Both of these species are typical of mossy, sandy pine forests. To our knowledge, this is new to Russia, Altay and Asia as a whole.

**Cortinarius nodosisporus Kytöv., Niskanen et Liimat. – Gorno-Altaysk, south of Mayma River, east of ski-lift, TEB 237-18 (LE 213081), TEB 238-18 (LE 312083) (Fig. 2d).

This species resembles C. uraceus and C. colymbadinus on the olive-grey-brown colours, including an olive-grey colour of veil remnants, and the darkening (blackening) of stipe context. However, it differs from these by the habitat in warm deciduous forests, and by the very strongly verrucose to spiny spore ornamentation. The species seems extremely rare, formerly only documented from two sites in Norway; the type site from the inner Sognefjord in rich (but not calcareous Tilia cordata scree forest (Liimatainen, 2014) and another site from the inner Oslofjord, in calcareous Tilia – Corylus forest (Brandrud et al., 2016). The report of C. zinziberatus in Ivanov and Durandin (1996) from dry Betula forests of the Volga basin, might, however, possibly cover our species. Cortinarius zinziberatus is nowadays usually regarded as a synonym to C. colymbadinus (Dima et al., 2014), a coniferous forest species resembling C. nodosisporus. There is a remarkable hiatus between these two verified localities in Norway, and our new, verified find in Gorno-Altaysk. Furthermore, also the habitat is different; in Gorno-Altaysk the species was found in calcareous Betula pendula forest, together with e.g. Cortinarius olearioides. This species is also occurring in the habitats where C. nodosisporus was found in Norway, and it is possible that these species more or less follow each other in the same, apparently quite discontinuous habitats throughout Eurasia. But it should be added that C. nodosisporus probably is much rarer than the former one. In fact, C. nodosisporus must be one of the rarest and most interesting finds during our Altay-expedition.

*Cortinarius parvannulatus Kühner s. auct. – Kokshi, TEB 226-18 (LE 312060).

This collection, verified by sequencing, is corresponding with C. parvannulatus sensu Brandrud et al (1990–2018). As other taxa in this group, this seems to prefer habitats with Salix and Populus and other boreal deciduous trees. Our Altay collection was very probably associated with Betula.

**Cortinarius privignipallens Kytöv., Niskanen et Liimat. coll. – east part, Kokshi, river delta, TEB 157-18 (LE 312097); TEB 164b-18 (LE 312372).

C. privignipallens is here treated collectively, including two, apparently dissimilar but close genotypes. The species in wide sense is sister to C. privignatus, and these taxa are little known and apparently only weakly morphologically differentiated (Schmidt-Stohn et al., 2017). The C. privignipallens–C. privignatus-complex resembles the frequent C. biformis, but the former has a more greybrownish pileus, lacks a yellow discolouring stipe (base), and has smaller, broadly ellipsoid spores. The C. privignipallens – C. privignatus-complex is presented in more detail by Schmidt-Stohn et al. (2017). Up to now, C. privignipallens was only reported from Sweden and Finland (Schmidt-Stohn et al., 2017). In Altay, the species was found and confirmed by rDNA ITS sequencing from a richer mossy-herb-rich Pinus (Betula) forest at the Kokshi delta, Teletskoye Lake. In Fennoscandia, this complex seems to be mainly associated with Picea abies. More samples are needed to see if it possible to distinguish the taxa in this complex by morphology and ecology.

**Cortinarius pseudofallax Carteret coll. – Gorno-Altaysk, TEB 247-18 (LE 312087).

This sequence-verified collection from calcareous Betula forest of Gorno-Altaysk belongs to the complex of C. pseudofallax – C. parvannulatus. Apparently, this one represents an undescribed taxon. The C. pseudofallax-complex will be taxonomically-phylogenetically treated in another paper (Toivonen, Dima, Brandrud et al., in prep.).

Cortinarius raphanoides (Pers.) Fr. – Kokshi, TEB 160-18 (LE 312100).

The species was found under Betula at the delta of Kokshi. This is one of the more widespread and common Betula-associated cortinarii, both occurring in oligotrophic-acid and richer/eutrophic sites (Brandrud et al., 1990–2018). The species is very widespread in Russia (known from 23 regions).

Cortinarius saniosus (Fr.) Fr. – Gorno-Altaysk, Biryula Village near Mayma River.

This widespread species is associated mainly with Betula, Populus and Salix. It is recorded from 20 regions of Russia.

**Cortinarius aff. roseocastaneus Niskanen, Liimat. et Kytöv. – Gorno-Altaysk, TEB 245-18 (LE 312088).

This species resembles taxa such as C. decipiens and C. subcastaneus. According to the ITS sequence, this probably represent a new, undescribed species, close to C. rosecastaneus.

**Cortinarius subheterocyclus Liimat., Niskanen et Kytöv. – Kokshi, TEB 230-18 (LE 315527).

Based on ITS-barcoding, it appears that the species formerly treated as C. heterocyclus, consists of three very close, semi-cryptic species. In addition to C. heterocyclus s.str., which was described by Soop (1990), the second and third taxa in the complex were recently described as C. subheterocyclus and C. heterocycloideus by Liimatainen et al. (2017). The complex constitutes of medium-sized, slender species with reddish (vinaceous brown) veil girdles or fibrils on stipe, sometimes also with vinaceous tinges at base. The complex belongs in sect. Brunneotincti. The reddish veil colour, possibly due to anthraquinonoid pigments, apparently often develops and becomes stronger with age (or on bruising), in contrast to the red antraquinonoid pigments occurring in the veils of sect. Armillati species (see Niskanen et al., 2011). Even though their reddish tinged veil make the species of the C. heterocyclus complex rather striking and easy recognisable at the group level, the species are rarely collected, and they seem to be rare everywhere. Cortinarius subheterocyclus is so far only reported from Finland, Sweden and Norway (Liimatainen et al., 2017). According to the protologue, the species grows in mixed deciduous forests, but always with Betula present (Liimatainen et al., 2017). Additional material sequenced from boreonemoral southwestern Norway confirms this habitat (pers. obs.). In Altay the species was found in mixed Pinus – Betula stand at the Kokshi delta. Based on the habitat knowledge, we assume that the species at Kokshi was associated with Betula.

**Cortinarius testaceofolius H. Lindstr. et Soop – Kokshi, TEB 156-18 (LE 315518).

The species is characterized by an often conico-campanulate pileus, vivid redbrown to brick-red lamellae (reminiscent of those of C. laniger), and an attenuate to subradicate stipe (Brandrud et al., 1990–2018). The species occurs in mossy pine-spruce forests, and our find from pine forest at Kokshi is the first report from Russia and Asia (Siberia).

*Cortinarius traganus (Fr.) Fr. – Kokshi, Chelush.

It is one of the more well-known and frequent cortinarii of the boreal taiga regions.

**Cortinarius turgidoides Rob. Henry – Kokshi, TEB 155-18 (LE 315539); TEB 222-18 (LE 312062).

This is a little-known and apparently rare species associated with rich sandy pine forests and more calcareous pine forests. The species resembles C. quarciticus, but is slenderer and has a slightly fibrillose pileus. This one is also apparently new to Russia and new to Asia.

*Cortinarius umbrinolens P.D. Orton – Bele, TEB 179-18 (LE 312094) (Fig. 3b).

The species was found in calcareous, semi-open Betula (Larix) steppe forest at Bele in the southeast part of Teletskoye Lake. C. umbrinolens is apparently strictly associated with Betula, usually in rather oligotrophic, acid, sometimes peaty habitats. The site at Bele apparently does not correspond well with these habitat-preferences, but the species was found growing directly on a much decayed, coarse Betula log, which probably provides a rather acidic, organic habitat.

**Cortinarius aff. vernus H. Lindstr. et Melot – Kamga bay, river delta, TEB 207-18 (LE 315519) (Fig. 3c).

The species was found in riparian forest with Betula pendula, Salix viminalis and Alnus viridis ssp. fructicosa at the large delta of Kamga bay. Cortinarius aff. vernus belongs to a complex with an entire series of genotypes, of which this seems to have no applicable species name. However, more studies in this complex is needed to draw firm conclusions about taxonomy and nomenclature. The species resembles C. casimiri, C. subcastaeus and C. vernus, becoming faintly vinaceous basally when bruised. The taxon might be an eastern one associated with Alnus viridis ssp. fructicosus, but could also be much overlooked. It is here reported new to Siberia, Russia and probably Asia as a whole.

Dermocyboid species

Dermocyboid species, that is taxa with a fibrillose pileus and with yellow and red antraquinonoid pigments, were not much found during our stay in Altay.

Cortinarius croceus (Schaeff.) Gray – Chelush, TEB 177-18 (LE 315533); TEB 138-18 (LE 315535).

Cortinarius malicorius Fr. – Baygazan, TEB 194-18 (LE 312076).

Cortinarius semisanguineus (Fr.) Gillet coll. – Kokshi, TEB 163b-18 (LE 315517).

Anomalioid species

The Anomali section was well-developed in Altay, with five species recorded, plus Cortinarius spilomeus, which belongs to a sister group (sect. Spilomei) and is here included. All taxa (except C. spilomeus) were found under Betula, both in grazed woodland, forest borders or along tracks near our village at Yaylu, but also under Betula in the mixed Pinus sibirica – Betula pendula (Abies sibirica) pristine forests on the steep slopes. This group seems to be among the most tolerant cortinarii for the luxuriant tall-herb vegetation and the eutrophic-nitrogen-rich conditions at these slopes. In Europe these are usually found in secondary, culturally influenced forests, but in Altay it was clear that these also have a place in primary, virgin forests, maybe favoured by forest-fire successions. Here, typical Betula associates, such as Cortinarius albocyaneus and C. azureovelatus (= C. xanthocephalus) were found.

*Cortinarius albocyaneus Fr. – Kokshi, TEB 220-18 (LE 312063), Gorno-Altaysk, TEB 242-18 (LE 315522).

The species belongs to a critical complex of more or less bluish species with rather pale, greyish pileus and with a slightly viscid pileus surface in moist weather (glossy and micaceous in dry weather – Dima et al., 2016). Different names such as C. tabularis and C. viscidulus have been applied here, and at the moment, sequencing is needed to distinguish with certainty the species in the complex. We have sequence-verified material of C. albocyaneus from calcareous Betula forest of Gorno-Altaysk. The species is not formerly reported from the region.

*Cortinarius azureovelatus P.D. Orton (= C. xanthocephalus P.D. Orton) – Kokshi, TEB 221-18 (LE 312082). Gorno-Altaysk, TEB 243-18 (LE 315531).

This is a stout, ochraceous species usually almost without bluish tinges. It often occurs in rather open, grassy woodlands, parks and margins of forests. In Altay we had sequence-verified collections from calcareous Betula woodlands (near Gorno-Altaysk) and Betula – Pinus sylvestris forest (Kokshi). The species is new to Siberia, but is known from several reports from European Russia (under the name Cortinarius xanthocephalus).

Cortinarius caninus (Fr.) Fr. – Kokshi, TEB 158-18 (LE 315516); Baygazan, TEB 191-18 (LE 312071).

The species is normally easy distinguished from other Anomali by its more vividly brown pileus and distinctly brown girdle on stipe. In Europe, this is a typical species of young Picea plantations after clear-cutting, but sometimes also with Betula (e.g. at margins of summer farms). Along the lake Teletskoye, it was also sequence-verified from pristine Pinus sibirica – Abies – Betula forest.

**Cortinarius epsomiensis P.D. Orton (= C. pastoralis Soop, H. Lindstr., Dima, Niskanen, Liimat. et Kytöv.; =C. anomalus subsp. campestris Soop) – Baygazan, TEB 188-18 (LE 312077) (Fig. 3d).

This taxon is an ecologically deviating Anomali, in that it often occurs in quite open, dry, calcareous habitats with Helianthemum, but is also reported several times from deciduous forests (Liimatainen, Ainsworth, 2018). The species was described as C. pastoralis by Dima et al. (2016). However, recently one has been able to sequence the old type of C. epsomiensis, described by Orton (1958), and has shown that this is conspecific with C. pastoralis, which then becomes a later synonym (Liimatainen, Ainsworth, 2018). The species is so far with certainty reported only from Sweden, Finland and Estonia (Dima et al., 2016), as well as Great Britain (Liimatainen, Ainsworth, 2018), and is new to Russia and Asia. In Altay, it was found in semi-open, tall-herb mixed virgin forest, probably associated with Betula pendula, possibly also with Populus tremula. The species probably has a wide boreal-temperate Eurasian distribution, as many other Anomali taxa.

*Cortinarius lepidopus Cooke – Kokshi, TEB 165-18 (LE 315536).

This is a slender species, being the most frequent taxon in oligotrophic coniferous forests with Picea and Abies. Formerly, this was frequently named C. anomalus. C. lepidopus was firstly reported from Western Siberia by Filippova and Bulyonkova (2017).

*Cortinarius spilomeus (Fr.) Fr. – Baygazan, TEB 187-18 (LE 312073).

The species was collected under Pinus sibirica in tall-herb forest of Baygazan. The material is sequence-verified, and represents C. spilomeus s.str. C. spilomeus s.str. is the most frequent taxon in the C. spilomeus-complex, and most reports of C. spilomeus from Russia probably refers to this (but should be verified by sequencing).

Phlegmacioid species

Remarkably few species of subgenus Phlegmacium were recorded during our Altay expedition. Only four phlegmacioid species were recorded at the Teletskoye Lake, all under Betula. Two additional ones were recorded under Betula at Gorno-Altaysk. C. porphyropus and C. triumphans were rather frequent along the Teletskoye Lake, and with the same habitat-requirements as the Anomali species discussed above; both in grazed forest (margins) near the settlements, as well as in the pristine mixed Betula-conifer forests. It should be noted that another, very rare phlegmacioid species, C. moseri, was collected here in 2001 by Henning Knudsen, in Alnus viridis subsp. fructicosa tickets (Moser, 2002).

This subgenus may show a very high diversity in some calcareous regions of Europe, but might almost lack in others. Also other studies from Western Siberia have found a low portion of phlegmacioid species, especially that of the Khanty-Mansiysk Region, where only 5 out of 69 Cortinarius species recorded were phlegmacioid (Filippova, Bulyonkova, 2017).

The reason for the scarcity of phlegmacioid species in the Teletskoye area seems to be the lack of calcareous forests suitable for cortinarii and many other mycorrhizal fungi. The calcareous sites visited apparently either had a too luxuriant and dense herb vegetation and/or the sites were apparently too eutrophic/nitrogen-rich. The only calcareous sites that showed a rich mycorrhizal funga, was the grazed Betula woodlands near Gorno-Altaysk, and here, the phlegmacioid species were playing a more important role (especially C. olearioides; see below). Calcareous Abies – Picea forests with calciphilous soil-dwelling fungi are very little documented from Siberia so far. M. Moser apparently found a couple of hotspots with some calciphilous Phlegmacium species (such as C. caesiocanescens) in Picea subovata-dominated forests along Chuya River (tributary to Katun) in Altay 2001 (according to herbarium IBF Ferdinandeum Innsbruck list provided by U. Peintner). Otherwise, the nearest well-documented hotspots with calciphilous, mycorrhizal fungi in black taiga are from the Ural in European Russia (Shiryaev et al., 2010).

Cortinarius infractus (Pers.) Fr. s.str. – Kokshi, river delta, TEB 213-18 (LE 312061), TEB 214-18 (LE 315529). Gorno-Altaysk, south of Mayma River, east of ski-lift, TEB 239(240)-18 (LE 312065) (Fig. 4a).

According to recent sequencing studies, this unit was divided into a number of genetically well-supported semi-cryptic taxa, with little morphological differentiation, but often well differentiated ecological (unpublished data). Material both from Teletskoye Lake (Kokshi) and from Gorno-Altaysk were sequenced, and both appear to be identically with C. infractus s.str., which is the only taxon in the group that seems to be occurring also in Betula forests. Our Altay finds were from a pine-dominated forest, but under Betula (Kokshi), and from pure Betula pendula forest (Gorno-Altaysk). So far, C. infractus s.str. is the only Infracti that is verified from Siberia. The species of the Infracti-group, although consisting of fleshy fungi with phlegmacioid characters such as viscid pileus, is phylogenetically isolated and rather far from the major phlegmacioid clades (Garnica et al., 2016; Soop et al., 2019).

Cortinarius largus Fr. – Gorno-Altaysk, Biryula Village near Mayma River, TEB 248-18 (LE 312066).

The species was recorded at the margin of a grazed, calcareous Betula forest. This is a widespread Eurasian species both in thermophilous deciduous forests as well as in Betula forests.

*Cortinarius olearioides Rob. Henry (= C. subfulgens P.D. Orton) – Gorno-Altaysk, south of Mayma River, east of ski-lift, TEB 233-18 (LE 312078), 234-18 (LE 312079) (Fig. 4b).

This was the only calciphilous phlegmacioid species observed during the expedition, and moreover, it was the only member of the large sect. Calochroi s.l. that was found. The species was found in a calcareous Betula pendula forest on steep slope adjacent to ski-lift, south of Mayma River at the south-east side of the city of Gorno-Altaysk. Here, the species produced fairy rings in a hot-spot also with large rings of the calciphilous telamonioid C. disjungendus and C. nodosisporus. In Europe Cortinarius olearioides is associated with calcareous, thermophilous deciduous forests with Quercus, Corylus, Carpinus and Tilia in nemoral-boreo-nemoral regions. In Scandinavia, the species follows more or less calcareous Corylus woodlands, or Corylus screes into the southern boreal zone (Brandrud, Bendiksen, 2001). The occurrences of C. olearioides in (warm) Betula-forests seem to be unique to Siberia. The species is also found and verified by sequence data from the Tomsk Region (Vaishlya, pers. comm.), and the species is probably associated with Betula also here, since there is no natural Quercus – Corylus – Tilia-forests in W. Siberia. The species is reported from 11 regions of Russia, and also reports under the name C. subfulgens, such as that from Quercus forests of the Volga basin (Iwanow, Durandin, 1996), very probably belong here. The species is not known from North America, and may not be distributed much farther east in Siberia, due to lack of, or strong discontinuity of such thermophilous, calcareous Betula (or Quercus –Tilia) sites.

Cortinarius porphyropus (Alb. et Schwein.) Fr. – Kokshi, TEB 151-18 (LE 315512); Chelush, TEB 176-18 (LE 315514); Baygazan, TEB 186-18 (LE 312070); Kamga bay in northeast, TEB 204-18 (LE 312069) (Fig. 4c).

The species, characterized by initially bluish colours and lilac staining when bruised, was one of the most common cortinarii in Altay, and it was also collected here by M. Moser in 2001. As far as we know, this is strictly associated with Betula (Saar et al., 2014). The species is known from 22 regions of Russia, and sequence-verified from the Tomsk region (Vaishlya et al., 2017). It seems to be very widely distributed and frequent throughout the boreal taiga-zone, from Scandinavia to Siberia-Altay, where Betula pendula or B. pubescens are everywhere important components of the coniferous forest. In montane Central and South Europe, the species is much rarer, due to scarcity of Betula.

**Cortinarius subporphyropus Pilát – Kamga bay in northeast, TEB 195-18 (LE 315521).

This is distinguished from C. porphyropus on the small, tiny basidiocarps and the larger spores. Furthermore, the habitat requirements of C. subporphyropus are not so strict, and it occurs with various deciduous trees. In Altay reserve it was found in riparian forest under Betula, Alnus and Salix. The species is new to Russia and new to Siberia and Asia.

*Cortinarius triumphans Fr. – Yaylu Village, TEB 184-18 (LE 312074). Gorno-Altaysk, south of Mayma River, east of ski-lift, TEB 241-18 (LE 312058) (Fig. 4d).

This well-characterized species with thick ochre brown veil girdles on stem and strict association with Betula spp. is used in Siberia as an edible mushroom. Along the Teletskoye Lake this was one of the more frequent cortinarii, occurring in various herb-rich habitats with Betula pendula. It was also collected along Teletskoe Lake by M. Moser in 2001 (list from herbarium IBF Ferdinandeum Innsbruck, provided by U. Peintner). Both this and C. porphyropus were in the tall-herb, pristine mixed forest slopes found mainly in places with remnants from former forest fires. This might indicate that these species prefer forest floors with thinner organic humus, with low nitrogen-levels, but it might also simply be due to the overrepresentation of Betula trees in successions after fire. According to Nezdojminogo (1983) the species is widespread in different parts of Russia, including Siberia. The species was, however, not noted in the study of the Abies – Picea – Pinus forests near Khanty-Mansiysk, including succession stages with much Betula pubescens. This might indicate that the species is more frequent in the southern boreal zone with B. pendula, than further north with B. pubescens, which is in correspondence with the situation in Scandinavia (Brandrud, 1996).

Myxacioid species

The morphology circumscribed subgenus Myxacium in phylogeny “falls apart” into some quite distantly related clades (Garnica et al., 2016). However, for practical reasons, we keep the grouping “myxacioid species”.

**Cortinarius croceocristallinus Rob. Henry var. alneti Bidaud – Kamga bay in northeast, TEB 196-18.

This is a small, white, bitter myxacioid species, characteristic of Alnus riparian forests. Unfortunately our tiny, single specimen found under Alnus viridis ssp. fructicosus got lost during the process of drying.

Cortinarius delibutus Fr. – Baygazan, TEB 189-18 (LE 312075).

The species was one of the few of our Cortinarius species which was not infrequent in the nitrogen-rich, tall-herb Pinus sibirica – Abies – Betula forests at Baygazan.

Cortinarius vibratilis (Fr.) Fr. – Kokshi.

The species is recorded from 14 regions of Russia, including Altay (Gorbunova, 2008).

Other groups

**Cortinarius boreicyanites Kytöv., Liimat., Niskanen et A.F.S. Taylor – Kokshi, TEB 152-18 (LE 315511).

According to recent studies, three phylogenetically well-supported species in the C. cyanites complex can be distinguished; C. cyanites s.str., C. boreicyanites and C. violaceorubens (Liimatainen et al., 2014a), of which C. boreicyanites seems to be the most frequent in boreal coniferous/birch forests. According to present data, these seem to be semi-cryptic species, and further studies on character variation are needed to see if these can be separated morphologically. This is the first report outside the Nordic countries for C. boreicyanites.

C. caperatus (Pers.) Fr. [= Rozites caperata (Pers.) P. Karst.] – Kokshi.

The species was met with once, in the Pinus – Be-tula forest at Kokshi delta. This well-known, edible species is widely distributed in Eurasia and North America, and is frequent in oligotrophic coniferous and deciduous forests of boreal North Europe. In Russia it is reported from 49 regions, including 13 in Siberia.