Protoblastenia pseudoterricola 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 pseudoterricola Pykälä & Myllys sp. nov.

Fig. 4 B

Diagnosis.

Differs from P. terricola in having a thinner thallus and hypothecium.

Type.

Finland • Enontekiön Lappi, Enontekiö, Kilpisjärvi, Saana , fell, steep NE-slope, dolomite rock outcrop, beneath NE-facing wall, on dolomite pebbles, 820 m a. s. l., 69°02'N, 20°51'E, 11 August 2011, J. Pykälä 44157 ( H 9235068 – holotype, GenBank accession number: PV 766697 ) .

Description.

Thallus white, rimose, ca. 0.05–0.1 mm thick, K-, UV + bluish-white. Apothecia orange (young apothecia) to dirty orange-brown, 0.3–0.8 mm, convex to strongly convex, superficial; ca. 30 apothecia / cm 2. Epihymenium orange-brown, 10–15 μm thick, K + violet. Hymenium 70 μm thick. Hypothecium dark reddish-brown to violet, ca. 60–100 μm thick. Ascospores 0 - septate, (7.9 –) 8.6–9.9 – 11.2 (– 12.4) × (4.5 –) 4.8–5.5 – 6.2 (– 7.0) μm (n = 20).

Habitat and distribution.

Only one specimen of this species is known. It was collected from dolomite pebbles beneath an NE-facing wall of a dolomite rock outcrop on the Saana fell (NW Finland). Companion species include Farnoldia jurana , Polyblastia inconspicua Savić & Tibell and Thelidium huuskonenii Pykälä & Myllys.

Etymology.

The name refers to the similarities in morphology and ITS to P. terricola .

Notes.

The species is closely related to P. terricola and P. violacea . Protoblastenia terricola has rimose to areolate thallus (when growing on rock) mainly exceeding 0.1 mm in thickness and an often thicker hypothecium. Protoblastenia violacea has orange apothecia and smaller spores. More material is needed to confirm whether these three species can be distinguished by morphology only. Protoblastenia westbergii resembles the new species, but has more densely occurring apothecia (ca. 40–160 apothecia / cm 2) and larger spores.

Figures

Figure 4. A. Protoblastenia pseudocompressa (holotype); B. P. pseudoterricola (holotype); C. P. remota (holotype); D. P. rikkinenii (holotype). Scale bars: 0.5 mm.