Protoblastenia arupii 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 arupii Pykälä & Myllys sp. nov.

Fig. 2 A

Diagnosis.

Differs from P. dolomitica and P. westbergii in having only a slightly rimose thallus.

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 44130 ( H 9250904 – holotype, GenBank accession number: PV 766636 ) .

Description.

Thallus grey, slightly rimose, ca. 0.02–0.05 mm thick, K-, UV-. Apothecia orange, 0.2–0.5 mm, slightly convex to convex, 1 / 2 - immersed in thallus; ca. 60 apothecia / cm 2. Epihymenium brown-yellow to orange-brown, 12–15 μm thick, K + violet. Hymenium 50–60 μm thick. Hypothecium red-violet, ca. 50–60 μm thick. Paraphyses ca. 1.5–2 μm thick, apex not thickened. Ascospores 0 - septate, (10.3 –) 11.8–12.8 – 13.8 (– 15.1) × (5.3 –) 5.7–6.8 – 7.8 (– 9.4) μm (n = 27).

Habitat and distribution.

Only one specimen has been found on the calcareous Saana fell in NW Finland. The species was associated with Polyblastia sp. and Rhizocarpon petraeum (Wulfen) A. Massal.

Etymology.

The specific epithet is in honour of Dr Ulf Arup (Lund) for his many important contributions on the taxonomy (particularly Teloschistaceae and Lecanoraceae ) and biogeography of especially Fennoscandian lichens.

Notes.

Protoblastenia arupii is related to P. dolomitica and P. westbergii in the ITS tree, although the relationship remains unsupported. The only known specimen is characterised by a thin red-violet hypothecium and large spores, some of them particularly broad. Protoblastenia dolomitica and P. westbergii differ in their rimose to areolate thallus and slightly narrower spores. An ITS marker as a DNA barcode may be needed for unambiguous identification.

Figures

Figure 2. A. Protoblastenia arupii (holotype); B. P. borealis (holotype); C. P. compressa (holotype); D. P. dolomitica (holotype). Scale bars: 0.5 mm.