Pertusaria inopinata Erichsen (1936: 99)

Oset, Magdalena, 2021, On the identity of some taxa of Pertusaria (lichens) described by C. F. E. Erichsen, Phytotaxa 497 (2), pp. 165-171 : 166-167

Pertusaria inopinata Erichsen (1936: 99)

Type:—[ GERMANY, Schleswig-Holstein] Bramsted, erratische Blöcke bei Bimöhlen , auf einer Weide , 27.05.1915, leg. Erichsen (lectotype HBG —designated here, Mycobank MB 10000452 ). Figure 1 .

The type specimen of Pertusaria inopinata is characterized by a hardly rimose, dark grey to olive-greenish, not areolated thallus, with numerous irregular, rounded, 0.2–0.3 mm wide, grey-whitish to olive-greenish soralia ( Figure 1). According to Erichsen (1936) the thallus reacts P+ yellow, K+ yellow, C–and I–. Norstictic acid and traces of lecanoric and gyrophoric acids were detected by own chemical analyses. This name was reported from Denmark ( Søchting & Alstrup 2002), Germany ( Erichsen 1936) and Poland ( Alstrup & Olech 1992).

The type of Pertusaria inopinata is morphologically and chemically concordant with Lepra excludens ( Nylander 1885: 296) Hafellner , in Hafellner & Türk (2016: 172) (syn. Pertusaria excludens Nyl. ). Therefore P. inopinata should be considered as a synonym of L. excludens .

During herbarium studies three original specimen of P. inopinata were found in HBG, one collected by Erichsen and annotated as ‘Typus’ consists of two pieces of stone with the same thallus ( Figure 1). The other two were cited in the protologue, but collected by Lettau and Schade. All samples studied correspond in morphological and anatomical characters with the description provided by Erichsen (1936). The chemistry of the type specimen annotated as ‘typus’ and other samples were checked by P. James and norstictic acid and traces of lecanoric and gyrophoric acid were detected ( Hanko 1983). The presence of these secondary metabolites is confirmed by own research.

Hanko (1983) cited as a ‘typus’ the specimen collected by Schade (“ DDR. Sachsen: Leusitzer Niederung 7.1936, Schade, HBG-1213”), but the data presented by Hanko (1983: 201) do not match those given in the protologue by Erichsen (1936: 99), therefore, his typification cannot be considered effective, and consequently, a new lectotype of P. inopinata is designated ( Turland et al. 2018).

Syntypes of P.inopinata examined. [ Germany] Thüringen: Manebach im Thüringer Wald, auf Porphyrsteinchen eines begrasten Waldweges , 750 m, leg. G. Lettau ( HBG) . [Sachsen] Krs. Bischofswerder, Oberputzkau , 325 m, 29.12.1936, leg. G. Schade ( HBG) .