NOTEWORTHY POLYPORES OF PUSHKIN CITY NEAR THE SAINT PETERSBURG (RUSSIA), THE RESERVE OF OLD-GROWTH TREES. 1. TRAMETES SUAVEOLENS

The paper opens a series focused on noteworthy polypores associated presumable with old-growth broadleaf trees in the Pushkin (Tsarskoye Selo) ensemble near St. Petersburg. Some nemoral species complexes are reserved here due to protection of old-growth trees over this area. The species in focus of the present paper is Trametes suaveolens (Polyporaceae, Agaricomycetes), the species with rather uneven taxonomical history. The basionym initially was applied to another fragrant polypore, and its nomenclature was stabilized rather recently, after its neotypification. This is a rare species associated presumable with large willow trees. In some countries (Britain, Montenegro, Finland, Estonia, some regions of Russia) this species is protected. Four habitats of this protected on St. Petersburg species were revealed in the Pushkin city. All these are documented and an enlarged morphological and ecological description of T. suaveolens is given. A new form T. suaveolens f. dorsalis was described.


INTRODUCTION
The opened series is focused on polypores, associated presumably with old-growth nemoral trees. Such trees are very rare in natural forests of Europe, because of maintaining here the strained forest management. Paradox enough, on some sites of city landscapes (e.g. parks, cemeteries, historical ensembles) there were prerequisites for preservation of old broadleaf trees exemplars. It is known also that during its aging the tree forms an expanding realm of niches, free for settling by various organisms, including the fungi. Noteworthy species of polypores, avoiding of oligotrophic habitats or presented there by leptosomic ecades, can reproduce self-population in association with an old broadleaf trees.
The Pushkin city (known also under name Tsarskoye Selo, Russia) represents a mosaic urban-parks landscape merged into trained hills on edge of the Izhora Plateau near the Saint Petersburg city. As the area of major tourist attraction the Tsarskoye Selo landscape ensemble was included in the list of monuments protected by the UNESCO. The Picea abies (L.) Karst. containing 1 Ivan V. Zmitrovich (iv_zmitrovich@mail.ru; IZmitrovich@binran.ru boreo-nemoral forests characteristic to this intra-zonal Izhora Vegetation Rayon (Alexandrova, Yurkovskaya, 1989) were cut, some additional drying works were carried out and this territory became comparable with those of Central European cities in their environmental plane. The Catherine Park was funded in 1750s, surrounding tree-stands were formed in 1800-1910s and rather wide range of broadleaf trees of the Pushkin parks has endured a bicentennial age. The main stand-formers here are Quercus robur L., Acer platanoides L. Fraxinus excelsior L. and Tilia cordata Mill.all these represent native element of cutted Picea abies-boreo-nemoral forests once widespread here. Also, two trees-formed willow species, Salix alba L. and S. fragilis L. as well as Alnus incana (L.) Moench and A. glutinosa (L.) Gaertn. were distributed here along the rivers. Additionally, Tilia platyphyllos Scop., Aesculus hippocastanum L., Acer rubrum L. were introduced into park and roadside landings. A lot of nemoral and boreonemoral shrubs were landed under bed curtains of the main stand-formers. Within them, Padus avium Mill., Sorbus aucuparia L., Malus spp., Crataegus spp., Acer negundo L., Caragana arborescens Lam., Corylus avellana (L.) Karst., Prunus domestica L., Frangula alnus Mill., Amelanchier sp., Cotoneaster lucidus Schltdl. are predominant.
The main purpose of this series is enlarged description of ecological polymorphism of noteworthy polypores species founded in Pushkin city (Tsarskoye Selo) territory and documentation of habitats of these organisms.
Later, Fries (1837) described the genus Trametes typified by Polyporus suaveolens (L. : Fr.) Fr. (Murrill, 1905) and this genus is widely accepted nowadays (Zmitrovich & Malysheva, 2013). However, the Linnaean name Boletus suaveolens L. was misapplied to type species of Trametes in Friesian sense and some authors beginning with Donk use the combination Haploporus suaveolens (L. : Fr.) Donk in application to the type species of Haploporus, but not Trametes (Donk, 1971). The consequent sanctioned and correctly applied synonym which substitutes an ambiguous Trametes-type would be Boletus discoideus Dicks. ("Acaulis planiusculus villosus rugoso-tuberculosus sordide albens poris labyrinthiformibus concoloribus. Nequaqum convenit cum B. suaveolente Linn., qui pulvinatus, superficie laevi, nec rugosa aut villosa; poris rotundatis, nec labyrinthiformibus". Cited according to J. Dickson, 1793). It was sanctioned by Fries in Index (1832, p. 57). The corresponding combination Trametes discoideus (Dicks. : Fr.) Rauschert was made by Rauschert (1990). However, in 1991 the name Boletus suaveolens L. : Fr. was neotypified by Ryvarden (1991), who has selected the specimen from Sweden (Upland, Uppsala, van der Post 1872, S) corresponded to Trametes suaveolens as neotype. Because the general principle of Nomenclatural Committee was to minimizeand indeed if possible preventname changes arising from the change of starting date, which is why names can be typified either on an element in the context of the original protologue or an element in the context of the sanctioning treatment, the Ryvarden's selection in this case was as something best decision (Art. 9.2 and 9.10 of ICBN, Prof. J. McNiell, pers. comm.).
In all the parts of Europe this is rather infrequent species gravitating in its distribution to large and presumably live Salicaceae trees. This species is included in a series of European Red lists (Kotiranta & Niemelä, 1996;Evans et al., 2006;Kasom & Miličković, 2006;Parmasto, 2009). In Russia, this species was entered in Red book of Leningrad Region (2000) and Red book of Saint Petersburg (2004). Our research on Pushkin area allows to reveal some populations of this interesting fungus. Material collection. A total of thirty kilometer quarters were subject to monitoring since 2012. Old-growth leaf-trees phytosphere was examined regarding existence of the polypore species. The fruitbodies were fixed on photo or collected in the case of necessity and and an existence of sufficient for reproduction quantity of a remained propagative structures of the fungus. In laboratory, -20 °C followed by frozing of material were carried out. The material is kept in mycological herbarium of the Komarov Botanical Institute of the Russian Academy of Sciences (LE).

MATERIALS AND METHODS
Material elaboration. The macroscopic descriptions were based on a study of fresh and dried specimens. Microscopic preparations were mounted from dried material in Melzer's solution, 10% ammoniacal Congo Red and 5% aqueous solution of KOH, using a LOMO Micmed-6 light microscope. The hyphal system was revealed and described according to updated technique (Zmitrovich et al., 2009). The size of mature spores was measured on 30 spores in distilled water and Melzer's solution. The taxonomic position of the species was based on recent molecular studies (Zmitrovich, Malysheva, 2013;Zmitrovich, Kovalenko, 2015), higher taxa are given according to Hibbett et al. (2014). Basidiomata annual or perennial, sessile, of trametoid habit, 4-15 cm wide and 2-4 cm thick, triquetrous to cushion-like in section, semicircular in outline, pilei plane or slightly convex; as a rule clustered, but in normal not decurrent and devoid of stipe. Upperside without a differentiated subpellis, subtomentose, villose, of fine bristly, more or less even, but in some specimens scrupose, uniformly white, then cream, then grayish-bloom. Context purely white, rather dense, suberose, homogeneous, with prominent anise odor when fresh, up to 3 cm thick. Margin initially obtuse or bolster-like, then acute, with sterile zone around the hymenophore, in abhymenial surface cream or with grayish shades. Hymenophore as a single tube layer up to 10 mm thick, white to honey-colored or isabelline. Pores normally 0.5-1.5 mm in diam., but in average 1-2 per mm, with thick dissepiments, angular, sinuose in some regions, white, cream to lightcoffee, or in some specimens near dissepiments initially becoming grayish-brown (Fig. 1a). Hyphal system dimitic with sympodially branched sclerohyphae. Generative hyphae 3-5.5 μm in diam., clamped, thin-walled, rarely branched. Sclerohyphae 2.5-8.5 μm in diam., thick-walled to subsolid, hyaline, acyanophilic, inamyloid; the branching pattern sympodial, moderate in internal tissues and regular near surfaces, mostly rectangular. Basidia 20-30 × 5-7.5 μm, clavate, 4-spored, with a basal clamp. Cystidia none, but hyphal pegs composed by generative hyphae are regular in the hymenium. Basidiospores 7.5-12.5 × (3)4-4.7 μm, shortcylindrical, in certain projections lacrymoid or amygdaloid, hyaline, thin-walled, inamyloid, acyanophilous. Substrata and ecology. T. suaveolens grows on living, rarely dry trees, stumps and fallen logs of Salix spp. In other parts of Europe the fungus is reported also on Populus, Aesculus, Alnus, Betula, Carpinus, Fagus, Fraxinus, Malus, Populus, Quercus, Salix, Tilia, and Ulmus (Ryvarden & Melo, 2014). Causes a white heart-rot. Basidiomata of T. suaveolens usually exist during a single season, but even in the boreal zone some fungi which colonize slantwise growing willows over river falls can develop wintering basidiomata capable to resume their active growth after warming. In this case fruit bodies can reach rather sufficient sizes.

RESULTS AND DISCUSSION
The most typical habitat of this fungus is presented by floodlands along rivers where arboriform willows are growing (Fig. 2). In urban landscapes, T. suaveolens is associated as a rule with old willows trees.
Distribution. EUROPE: United Kingdom, Norway, Germany, Italy, Georgia, Finland, Russia. ASIA: Russia, Mongolia, Taiwan, China, S. Korea, Japan. NORTH AMERICA: USA, Canada (Global.., 2016). The distribution of this species over Pushkin (Tsarskoye Selo) territory is rather scarce. Only 4 habitats are revealing (Table), and only two deviated specimens were collected, since the populations of T. suaveolens are protected on Saint Petersburg territory (see also Fig. 2, 3).  Table. Morphological variability. In a field, the fungus can be recognized due to its rather large basidiomata with plane to convex subtomentose to villose pilei of uniform coloration. Cap zonation or radial color alterations are not characteristic for this species. Only near the margin some grayish shades can be observed in some representatives. The upperside relief normally even, but some obscure ridges or pimples can be expressed, especially when the basidiomes are merged into plant sprouts around basic trunk. The wintering basidiomata bear as a rule stramineous upperside and honey-colored tubes (Fig. 1b). Microscopically, this is rather invariable species, characterized by large basidia and basidiospores. Vegetative hyphae are typical for Trametes species. The hyphal system containing both weakly and strongly branched sclerohyphae was described as trimitic (e.g. Ryvarden & Gilbertson, 1993, 1994, but in a reality the binding hyphae represent an apical branches of skeletal dendrites merely, therefore we deal with a kind of dimiticism (Zmitrovich & Malysheva, 2013).
Three forms are known for this speciesf. inodora Fr. in Pilát, characterized by absence of any odor, f. gibbosiformis Nikol. in Bondartsev, characterized by smaller pores 2-2.5 per mm, f. griseopora Komarova, characterized by gray-coffeate shades already in young tubes of the fungus, and f. dorsalis ined., characterized by dorsally attached basidiomes with narrow reflexed border. Within aforementioned forms, two last ones were registered in Tsarskoye Selo together with type form and they will be characterized below.
Ann additional material was founded by us in the Pushkin vicinities growing on fiving willow tree on valley of the Kuzminka river. A short description of additional material follows.