Notes on Finnish Agaricales. R. Tuomikoski. Botanical Institute, Helsinki University. I. Remarks on our representatives of the genus Leccinum ( Boletaceae ). The genus Leccinum S. F. Gray em. Snell Rostk.) or as a subspecies (Leccinum scabrurn (Krombho!zia Karst., Trachypus Bat., Kromb­ ssp. niveum (Fr.) Sing.) . So far as I am awar e, ho!zie!la Maire) is known as a polymorphous it shows the same color reactions ·as the common and notoriously difficult group. Our Leccinums forms with brownish cap: the flesh of the cap have usually been treated traditionally, :l'ollow­ remains unchanged or takes only a faint rufous ing Karsten (1876, 1889), as two species call­ tint when exposed to the air, and turns pale ed Boletus scaber and B. versipenis (or rufus). greyish-blue with FeS04; in old specimens This grouping of the forms is (with the except­ parts of the flesh are usually greyish-green, and ion of. the characteristic species L. duriusculum become brownish blood-red with KOH. The sensu Sing.), in fact, quite natural, but it lumps white form is apparently widely disributed in a number of interesting types together. A more the Finnish area and quite common on suitable detailed study of the genus in Finland has seem- habitats, such as bogs, bog margins, boggy a nd ed desirable. The follow ing remarks on the swampy woodlands, etc. All I can say concern- Finnish Leccinums do not pretend to be more ing its t axonomic status, is that it seems not to than a first step in this direction, being based be a mere habitat form produced by differences on somewhat superficial studies without detailed in external conditions but probably genotypic­ microscopical and chemical analysis. The ally distinct from the commoner forms with a nomenclature followed is that of Singer (1947, brownish cap, judged from the fact that it often 1951). grows side by side with these on seemingly identical habitats. 1. Leccinum duriusculum (Schulz. in Fr. sen­ There is a scabrum type which seems to be su Sing.) Sing. more distinct than the white one. It has a grey, Syn.: Boletus pseudoscaber Kallenb., non fuscous or blackish pileus (often with lighter Seer., B. nigrescens Huber, non Rich. & Roze, B. Carpini (R. Schulz) Pears., B. rugosus Fr. coloured dots or stripes in places which have sensu Pilat, etc. long been covered by fallen leaves, grass, etc.) Apparently rare and southern, found only and blackish or grey scales on the stem, some­ quite recently in two localities in southernmost times arranged in rows forming an indistinct Finland, in both places in the vicinity of Cory­ elongated network. The flesh of the cap is per­ lus, Quercus, and Betula (presumably dependent haps somewhat firmer than in the other forms of of Corylus) : - V. Bromarv, Framnas, Sept. 6th L. scabrum, and does not in old specimens show 1952 (R.T.). - U. Espoo, Bodom, Aug. 11th 1952 any marked tendency to turn greyish-green nor (R.T.) . to become tinged blood red when tested with KOH. What makes this type of special interest 2. Leccinum scabrum (Fr.) S . F. Gray. is · the colour change of its flesh which, in not Syn.: Boletus scaber Fr., Krombholzia scabra (Fr.) Karst., Boletu s leucoph.aeus Pers. according too old specimens, becomes distinctly pink to some (French) authors, Trachypus !euco­ (bluish with FeS04), except at the base of the phaeus (Pers.) Favre, etc. stem where it often changes to green or bluish­ The collective Leccinum scabrum is very com­ green (which colour turns bright yellow with mon under birches (Betula) throughout the KOH). Damaged (slug-eaten, etc.) parts of the country. It shows a wide range of' variation in stem base usually show the blue-green colour. cap colour from almost white to blackish-grey. In old specimens the colour changes are not The whitish form, called Krombholzia scabra so marked as in young ones, and such specimens var. nivea by K a r s t e n , is nowadays often are not always easy to distinguish from more treated as a separate species (Boletus holopus typical forms of L . scabrum. In dried specimens 26 the discoloration has disappeared, and the flesh where within our area in the vicinity of birches is greyish-white (not brownish-white as in (Betula). I have observed it in numerous local­ typical scabrum). ities from the south coast to northernmost Finn­ This variety is not unlike some forms of Bo­ ish Lapland (Inari, Utsjoki, Enontekio) and to letus pseudoscaber as depicted by K a 11 en­ Finmarken in northernmost Norway. According b a c h (1935), i.e. Leccinum duriusculum sen­ to the literature it is a circumpolar species with su Singer, but it differs in the cuticle of the cap, a range extending to the Arctic tundra, and which is of the same type as in other forms of seems to be on the whole more northern than the collective L. scabrum (only differently co­ L. aurantiacum. I have seen it in some places loured) and thus without sphaerocysts, and also in Newfoundland. in the flesh which does not blacken. Krombhol­ L. testaceoscabrum is not very variable in zia scabra var. coloratipes Sing. is described by Finland. Wholly white forms probably belong­ its author as having light coloured scales on the ing to this species are occasionally observed, and stem and the stem becoming dotted with yellow it is not quite clear whether the forms with or blue; no mention is made of the blackish-grey brown cap and black scales on the stem (see colours so characteristic of our variety. In an under L. aurantiacum, p. 28) really belong to earlier paper (1950) I referred to this variety as L. aurantiacum or rather to L. testaceoscabrum. " Boletus sp.", assuming that it will probably prove to deserve recognition as a special taxo­ 4. Leccinum aurantiacum (Roqu.) S. F. Gray. nomical entity more than the other scabrum L. aur.antiacum differs from the last mention­ forms. With some hesitation I now try to iden­ ed species e.g. in colour, the cap being usually tify it with Singe r' s (1942, p. 36) Krombholzia more orange or reddish, and the young pores scabra var. roseofracta, admitting that the relat­ being whitish or creamy. The species occurs ion with other types, especially Leccinum oxy­ here in at least three colour races which appear dabile (Sing.) Sing., is still obscure to me. remarkably constant. Leccinum scabrum var. roseofractum is not a) "The white - stem me d form". Stem, rare, at least not in the southern half of Finland including the scabrosities, white, these becoming where it is found under birches on the same rufous in old specimens, cap lighter coloured habitats as the "typical" L. scabrum and the than in the other varieties. This race seems to variety niveum, especially in boggy forest land be common in the southern half of the country, among Sphagnum. S i n g e r has collected his where it has been observed in several localities, var. roseof?·actum near our area in the Lenin­ apparently exclusively in the vicinity of' aspens grad district of USSR growing "in sphagnusen (Populus tremula). Waldschneisen", and says of it: "Falls konstant, b) "The brown - s c a 1 e d form". Sca­ eine besondere Subspecies". I have repeatedly brosities of the stem almost from the start dark seen it growing together with the brown and reddish brown, cape of the same colour. Not white forms of L. scabrum and, as it seems, al­ rare, at least not in the southern parts of Fin­ ways distinct from these. It apparently also- oc­ land, mostly, if not always, together with aspen curs elsewhere within the area of L. scabrum. (Populus tremula). c) "The b 1 a c k- s c a 1 e d form". Scales 3. Leccinum testaceo-scabrum (Seer.) Sing. of the stem greyish-white in quite young spe­ Syn.: Boletus rufescens (Seer.) Konr., etc. cimens only, soon turning darker grey to black The collective "Boletus versipellis" is anything in exposed parts of the stem (the whitish-grey but homogenous, and its division into two spe­ colour remains long visible in the more protect­ cies is wholly justified and commonly accepted. ed parts, especially in the extreme base and The commonest of the two in Finland is Lecci­ tip), cap dark red. Occurs in the whole country num testaceoscabrum, better known as Boletus in heathy or mossy pine (and spruce?) woods, 1·utescens or Krombholzia rufescens. It differs also where birches, aspens, and all other decid­ from the other species (L. aurantiacum), both in uous trees are totally absent. The fungus is of the more yellow colours of the cap, beautifully the size and stature of L. testaceoscabrum, and contrasting w ith the colour of the stem which the scales of the stem are greyish-black in old has, even in young specimens, black scales on specimens, much as in that species. The pores white ground, and! also by the dingy olive grey in young specimens are, however, not dull olive pores in the young carpophores. as in L . testaceoscabrum, but creamy-whitish or L. testaceoscabrum is ve-ry common every- pallid as in L . aurantiacum. The darker, more 27 reddish colour of the cap, which is due to a and blackish scales on the stem), but with the bright pigment in the hyphae of the cuticle, flesh changing colour as in the group "versipel­ points definitely to L. aurantiacum and not to lis". These forms are not unlike the ones called L. testaceoscabrum. Boletus duriusculus by some authors (not Sin· This pine wood aurantiacum I have found g e r).