Protoblastenia saanaensis 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 saanaensis Pykälä & Myllys sp. nov.

Fig. 5 A

Diagnosis.

Differs from P. minuta in apothecia not leaving pits, from P. rikkinenii in having more densely occurring apothecia, from P. fennoarctica in having a thinner hypothecium and from P. timdalii in often having smaller apothecia.

Type.

Finland • Enontekiön Lappi, Enontekiö, Kilpisjärvi, Saana Nature Reserve , fell, steep SW-slope, dolomite rock outcrop, SW-slope, on dolomite pebbles, 835 m a. s. l., 69°02'N, 20°50'E, 14 August 2011, J. Pykälä 44431 ( H 9250945 – holotype, GenBank accession number: PV 766707 ) .

Description.

Thallus white, grey or pale brown, rimose to areolate, areoles 0.3–0.8 mm, ca. 0.03–0.1 mm thick, K-, C-, UV-, algal cells 5–12 μm. Apothecia yellow to orange-yellow, 0.3–0.5 mm, slightly convex to strongly convex, 3 / 4 - immersed to superficial; ca. 20–80 apothecia / cm 2. Epihymenium orange-yellow, 12–17 μm thick, K + violet. Hymenium 50–70 μm thick. Hypothecium pale yellow (some orange-yellow in squash), ca. 40–100 μm thick. Paraphyses ca. 2–2.5 μm thick, apex not thickened to slightly thickened, branching. Ascospores 0 - septate, (5.4 –) 7.1–8.4 – 9.7 (– 11.4) × (3.8 –) 4.3–4.8 – 5.4 (– 6.1) μm (n = 47).

Habitat and distribution.

The species has only been found on the calcareous Saana fell in NW Finland. The specimens are from a dolomite stone and dolomite pebbles in sun-exposed to rather shady habitats. Companion species include Acarospora glaucocarpa .

Etymology.

The name refers to the Saana fell where both known specimens were collected.

Notes.

The species is most closely related to P. timdalii (ca. 5–6 % difference in ITS) from which it is difficult to distinguish by morphology. It may have slightly smaller apothecia and spores. It also resembles P. minuta and the closely-related P. rikkinenii in having similar small spores. The only known specimen of P. minuta has apothecia which leave shallow to deep pits. Protoblastenia rikkinenii has sparsely occurring apothecia. Protoblastenia fennoarctica resembles P. saanaensis , but usually has a thicker hypothecium, slightly larger spores and sometimes plane apothecia.

Other specimens examined.

Finland • Enontekiön Lappi, Enontekiö, Kilpisjärvi, Saana Nature Reserve , fell, steep SW-slope, dolomite rock outcrop, under overhanging SW-facing wall, on dolomite stone, 835 m a. s. l., 69°02'N, 20°50'E, 14. 8. 2011, J. Pykälä 44438 ( 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.