Protoblastenia oulankaensis Pykälä & Myllys, 2025

Pykälä, Juha & Myllys, Leena, 2025, Unexpected species richness of the lichen genus Protoblastenia (Lecanorales, Psoraceae) in Finland, MycoKeys 124, pp. 193-226 : 193-226

Protoblastenia oulankaensis Pykälä & Myllys sp. nov.

Fig. 3 D

Diagnosis.

Differs from P. lilacina in often having slightly larger and more sparse apothecia and an often thicker hypothecium.

Type.

Finland • Koillismaa, Salla, Oulanka National Park, W of Savikoski , cliff, dolomite rock outcrop, on NE-facing wall, 190 m a. s. l., 66°25'N, 29°10'E, 17 August 2010, J. Pykälä 40201 ( H 9224130 – holotype, UPS – isotype, GenBank accession number: PV 766686 ) .

Description.

Thallus white to whitish-grey, endolithic, farinose or rimose, ca. 0–0.1 mm thick, K-, C-, UV- to UV + bluish-white, algal cells 5–9 μm. Apothecia orange to dark orange, 0.3–0.9 mm, convex to strongly convex, 1 / 4 - immersed to superficial, often leaving shallow pits, K + weakly red; ca. 10–50 apothecia / cm 2 (in one specimen, ca. 50–80 apothecia / cm 2). Epihymenium dark orange-brown, 12–25 μm thick, K- to K + orange or carmine red. Hymenium 70–120 μm thick, with oil droplets, in one specimen, partly violet in few apothecia. Hypothecium colourless to yellow, more rarely patchily red-brown, ca. 60–220 μm thick. Paraphyses ca. 2–3 μm thick, apex not thickened to slightly thickened, sparingly branched and anastomosing. Ascospores 0 - septate, (8.8 –) 11.8–13.9 – 16.0 (– 18.8) × (5.2 –) 6.6–7.4 – 8.2 (– 9.6) μm (n = 92).

Habitat and distribution.

The species occurs only in the Oulanka area in the parishes of Kuusamo and Salla in NE Finland. It grows on N- and S-facing walls of dolomite rock outcrops. Companion species include, for example, Diploschistes gypsaceus (Ach.) Zahlbr. , Gyalecta jenensis (Batsch) Zahlbr. , Lempholemma isidioides (Nyl. ex Arnold) H. Magn. , Protoblastenia borealis , Sagiolechia protuberans , Scytinium parvum , Verrucaria foveolata and Xanthocarpia crenulatella (Nyl.) Frödén, Arup & Søchting s. lat. Based on the ITS phylogeny, one GenBank specimen of P. lilacina from northern Italy ( AY 425629 ) belongs to P. oulankaensis (Fig. 1 ).

Etymology. In Finland, the species occurs only in the Oulanka area in the northeast.

Notes.

Protoblastenia oulankaensis is closely related to P. lilacina , but differs clearly from that species in its ITS profile (10 % difference). It is also morphologically rather similar to P. lilacina , having a weak K + reaction of apothecia and large spores. Protoblastenia oulankaensis tends to have slightly larger apothecia, which usually occur more sparsely (in most specimens ca. 10–50 apothecia / cm 2) and, on average, a thicker hypothecium. Protoblastenia lilacina is only known from the hemi-boreal zone of SW Finland, ca. 800 kilometres south to south-west.

Other specimens examined.

Finland • Koillismaa, Salla, Oulanka National Park, Savikoski 300 m N , Pinus sylvestris - forest, steep N-slope, dolomite rock outcrop, on NW-facing wall, st pc – sp, 180 m a. s. l., 66°25'N, 29°10'E, 10. 8. 2010, J. Pykälä 39629 ( H) ; • Salla, Oulanka National Park, Savilamminniemi, shore of Savilampi Lake , cliff, dolomite rock outcrop, on E-facing wall, sp, 180 m a. s. l., 66°25'N, 29°10'E, 12. 8. 2010, J. Pykälä 39810 ( H) ; • Salla, Oulanka National Park, Savilampi 1.4 km NE, bank of Savinajoki river , cliff, dolomite rock outcrop, upper slope, on NE-facing wall, 192 m a. s. l., 66°26'N, 29°11'E, 23. 8. 2011, J. Pykälä 44928 ( H) ; • Salla, Hautajärvi, Kurtinniittykuru , dolomite rock outcrop, on SW-facing wall, 195 m a. s. l., 66°26'N, 29°09'E, 24. 8. 2011, J. Pykälä 44949 ( H) ; • Salla, Hautajärvi, Kurtinniittykuru , dolomite rock outcrop, on SE-facing wall, 195 m a. s. l., 66°26'N, 29°09'E, 24. 8. 2011, J. Pykälä 44953 ( H) ; • Kuusamo, Juuma, Myllyniemi , dolomite rock outcrop, on NE-facing wall, 235 m a. s. l., 66°16'N, 29°22'E, 11. 8. 2020, J. Pykälä 55995 ( H) .

Figures

Figure 1. Phylogenetic relationships of the studied Protoblastenia species, based on a Maximum Likelihood (ML) analysis of the ITS dataset. Maximum likelihood bootstrap values > 50 % are shown at nodes. Thickened lines indicate bootstrap values > 70 %. New species described in this study are indicated with shadowed boxes. GenBank accession numbers for sequences downloaded from GenBank and collection numbers for the specimens sequenced for this study are shown after the taxon names. Holotype specimens of the new species are shown in bold.

Figure 3. A. Protoblastenia ekmanii (holotype); B. P. fennoarctica (holotype); C. P. minuta (holotype); D. P. oulankaensis (holotype). Scale bars: 0.5 mm.