Protoblastenia timdalii 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 timdalii Pykälä & Myllys sp. nov.

Fig. 5 B

Diagnosis.

Differs from P. saanaensis in having slightly larger apothecia and spores.

Type.

Finland • Enontekiön Lappi, Enontekiö, Kilpisjärvi, Saana , fell, steep NE-slope, dolomite rock outcrop, on NE-facing wall, 820 m a. s. l., 69°02'N, 20°51'E, 11 August 2011, J. Pykälä 44177 ( H 9250946 – holotype, O – isotype, GenBank accession number: PV 766711 ) .

Description.

Thallus white, grey or pale brown, endolithic, rimose to areolate, areoles 0.1–0.4 mm, ca. 0–0.15 mm thick, K-, C-, UV-. Apothecia yellow-orange, 0.3–0.8 mm, convex to strongly convex, semi-immersed to superficial; ca. 40–60 apothecia / cm 2. Epihymenium brown-yellow to dirty yellow, K + violet. Hymenium 60–70 μm thick, pale, partly yellow. Hypothecium colourless to yellow, ca. 60–100 μm thick. Paraphyses ca. 2–2.5 μm thick, apex not thickened to slightly thickened. Ascospores 0 - septate, (6.8 –) 7.9–9.2 – 10.5 (– 12.6) × (3.8 –) 4.2–4.8 – 5.5 (– 7.0) μm (n = 46).

Habitat and distribution.

Two specimens are known from the calcareous fells of Enontekiö, one from a NE-facing wall of a dolomite rock outcrop and one from dolomite stones on Dryas octopetala heath. This suggests that the species may have considerable microhabitat variation on the fells. Companion species include Halecania alpivaga , Polyblastia spp. and Thelidium auruntii .

Etymology.

The name is in honour of Prof Einar Timdal ( Oslo) for his numerous important contributions to the taxonomy, biogeography and conservation of Fennoscandian lichens, including studies on the related genus Psora and an important technical edition of the Nordic lichen journal Graphis Scripta.

Notes.

The species is most closely related to P. pseudoincrustans ined. This undescribed species differs in having plane to convex apothecia, a thick hymenium (80–115 μm thick) and larger spores (mean 12 × 7 μm) ( Kainz and Rambold 2004). However, in our phylogeny, P. pseudoincrustans is divided into two species. The closely-related P. saanaensis (differing ca. 5 % in ITS) is also morphologically very similar to P. timdalii . Protoblastenia saanaensis may have slightly smaller apothecia and spores, but more material is needed to confirm this.

Other specimens examined.

Finland • Enontekiön Lappi, Enontekiö, Porojärvet, Toskalharji, 1.2 km NE of Toskaljärvi , fell, SW-slope, gentle E-slope, Dryas heath, on dolomite stones, 875 m a. s. l., 69°12'N, 21°28'E, 5. 8. 2011 J. Pykälä 43624 ( H) .

Figures

Figure 5. A. Protoblastenia saanaensis (holotype); B. P. timdalii (holotype); C. P. violacea (holotype); D. P. westbergii (holotype). Scale bars: 0.5 mm.