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.