Puttea duplex (Coppins & Aptroot) M.Svensson

Svensson, Mans, Ekman, Stefan, Klepsland, Jon T., Nordin, Anders, Goeran Thor,, Hirschheydt, Gesa von, Jonsson, Fredrik, Knutsson, Tommy, Lif, Mattias, Toby Spribille, & Westberg, Martin, 2017, Taxonomic novelties and new records of Fennoscandian crustose lichens, MycoKeys 25, pp. 51-86 : 72-74

Puttea duplex (Coppins & Aptroot) M.Svensson comb. nov.

Fellhanera duplex Coppins & Aptroot, Lichenologist 40: 368 (2008). - Type: Wales, V.C. 46, Cardigan, Cwm Rheidol, Coed Simdde-lwyd NNR 22/(SN)/718.785, alt. 200 m, open valley-side Quercus petraea woodland, on Hypnum 'drip tassel’ on trunk of fairly well-lit, S-facing Q. petraea , 15 April 2001, S. P. Chambers (E-00169970, holotype, seen by MS; GZU, isotype, not seen).

Remarks.

New to Sweden. Originally described from Scotland and Wales ( Coppins and Aptroot 2008), and was recently reported from Norway ( Tønsberg 2016).

When describing this species, Coppins and Aptroot (2008) assigned it to Fellhanera on account of its similarity to F. margaritella (Hulting) Hafellner. Subsequently, F. margaritella was transferred to Puttea by Stenroos et al. (2009). Puttea was initially monotypic, but Stenroos et al. listed several other candidates for inclusion, of which two were later combined into the genus: P. exsequens (Nyl.) Printzen & Davydov ( Davydov and Printzen 2012) and P. caesia (Fr.) M.Svensson & T.Sprib. ( Dillman et al. 2012). P. duplex is distinct from the other three species by having 16-24 ascospores per ascus, but otherwise fits well in Puttea on account of having minute, pale apothecia, asci with a KI+ blue tholus penetrated by a canal that slightly widens towards the apex, and crystals that dissolve in K in the epihymenium and hymenium.

According to Coppins and Aptroot (2008), the exciple of P. duplex is paraplectenchymatous, which would be consistent with a placement in Fellhanera ( Lücking 2008), while Puttea margaritella (the type species of that genus) has a strongly gelatinized exciple composed of branched, parallel hyphae ( Stenroos et al. 2009). Although the exciple of P. duplex is often poorly developed and difficult to observe, we found that it is in fact quite similar to that of P. margaritella , being strongly gelatinized and consisting of dichotomously branched hyphae with narrowly cylindrical cell lumina.

The Swedish specimen was found on bark of Betula in a mature coniferous production forest. The specimen differs from the original description in having longer ascospores (-9 µm versus -5 µm) and by growing directly on bark and not over bryophytes. However, as the original description of F. duplex was based on only three specimens, the range of variation in ascospore size is possibly larger than indicated there and the ecology of the species may likewise be broader. Since the Swedish specimen agrees well with the holotype in other respects, we prefer to include it in P. duplex pending further studies.

Additional specimen examined: SWEDEN: Hälsingland, Bollnäs par., 8,5 km SW of Hanebo church, 1 km S of Hällbo, SE of Skidtjärnen, on stem of living Betula pubescens (23 cm diam.) in mature coniferous forest, alt. 120 m, 61°12'N 16°25'E, 22 August 2012, F. Jonsson FU9206 (UPS L-786606).