Caprettia lichexanthotricha Aptroot & M.F. Souza sp. nov. (Fig. 11)
MycoBank number: MB 551453; Index Fungorum identifier: IF 551453; Facesoffungi number: FoF 10423;
Etymology: From lichexanthone and tricha (hair).
Holotype: CGMS 82022
Thallus pale greenish grey, dull, almost dusty, thin, covering an area of up to 10 cm diam., without prothallus. Algae trentepohlioid, green, c. 10–17 x 7–12 µm, partly escaping from the thallus and becoming filamentous. Sexual morph: Undetermined. Asexual morph: Conidiomata pycnidial, densely covering the thallus, superficial, tubular, not tapering, with a dull black, partly (especially often at the tips) white pruinose, often branched, hair-like beak of c. 0.3–0.5 x 0.1 mm. Conidiophores hyaline, c. 1 µm wide. Conidia hyaline, bacillar, c. 4–4.5 x 1.5 µm, mostly agglutinated together in gelatinous masses with c. 100 conidia.
Chemistry: Thallus patchily UV+ yellow, with lichexanthone.
Material examined – Brazil, Paraná, Guaraqueçaba, Tagaçaba, 10 m alt., on tree bark, October 2020, A. Aptroot & M.F. Souza (82022, CGMS, holotype).
Notes: Caprettia Bat. & H. Maia is a small genus in the Monoblastiaceae Walt. Watson (Hongsanan et al. 2020). So far eight species are known, all exclusively from South America. Most of the species are foliicolous and have a very inconspicuous thallus. The new species is the first with lichexanthone and the first reported with secondary metabolites.
Figure 11 – Caprettia lichexanthotricha (CGMS 82022, holotype). A. Thallus under 365nm UV light. B. Thallus under normal light.