Ocellularia psorirregularis Aptroot, L.A. Santos & M. Cáceres, sp. nov.
Index Fungorum number: IF 902391; Mycobank number: MB 902391; Facesoffungi number: FoF 16050; Fig. 1
Etymology – Named after the chemistry and the irregular soredia.
Holotye – ISE 42001
Thallus crustose, discontinuous, following the surface of the substratum, not corticate, dull, pale creamish white, up to 5 cm diam., under 0.1 mm thick, not surrounded by a prothallus. Soralia of thallus colour or brighter white, irregular, 0.1–0.3 mm wide and high. Soredia granular. Photobiont trentepohlioid. Ascomata and pycnidia not observed.
Chemistry – Thallus UV–, K–, P+yellow. TLC: psoromic acid.
Ecology and distribution – On tree bark in primary rain forest; only known from Brazil.
Material examined – Brazil. Bahia: Chapada Diamantina, Lençois, Serrano along Rio de Lençois, alt. 500 m, 12° 34ʹ S, 41° 23ʹ 55ʹʹ W, on siliceous rock along river, 24 Jul. 2017, M.E.S. Cáceres & A. Aptroot (ISE 42001, holotype; isotype in ABL herbarium).
GenBank number – OR759505.
Note – This species is well characterized by its soredia and the presence of psoromic acid. So far, very few sorediate species are known in the genus (see e.g., Sipman et al. 2012), and only one of those, viz. O. microsorediata Rivas Plata & Lücking (Rivas Plata and Lücking 2012) contains psoromic acid. That species has however a corticate green thallus and more or less reticulte soredia. Its mtSSU sequence is identical to O. plicata Rivas Plata & Lücking (Rivas Plata and Lücking 2012), which is however a non-sorediate species. Similar cases where different species have identical mtSSU sequences have been reported before, even in the genus Ocellularia, by Kraichak et al. (2014).
Figure 1 – Ocellularia psorirregularis (ISE 42001, holotype). Width of picture=6 mm