Gassicurtia pruinosa M.F.Souza & Aptroot, 2021

Aptroot, André & Souza, Maria Fernanda, 2021, New lichen species and records from the Chapada dos Guimarães, Mato Grosso, Brazil, Cryptogamie, Mycologie 20 (10), pp. 171-180 : 177-178

Gassicurtia pruinosa M.F.Souza & Aptroot , sp. nov.

( Figs 3 , 4 )

MYCOBANK. — MB 839654.

Corticolous Gassicurtia without anthraquinone, differing from G. catasema (Tuck.) Marbach by theUV-negative thallus, apothecia brown pruinose, UV+ green, probably due to a xanthone, and ascospores 10-12 × 2.5-3.5 µm.

TYPE. — Brazil, Mato Grosso, Cuiabá, Chapada dos Guimarães , Pousada do Parque private area, alt. 700 m, 15°26’50”S, 55°49’50”W, on bark, 12-19.IX.2020, A.Aptroot & M.F.Souza 81917 (holo-, CGMS [ CGMS]; iso-, ABL [ ABL]).

ADDITIONAL MATERIAL EXAMINED. — Brazil. Mato Grosso: Same details as the holotype, A.Aptroot & M.F.Souza 81496 (para-, CGMS).

DESCRIPTION

Thallus crustose, greenish grey, areolate, very variable in thickness, partly almost immersed, areoles irregular, c. 0.1 mm diam., thallus surrounded by a c. 0.3 mm wide, brown hyphal prothallus line. Isidia and soredia absent. Apothecia sessile, solitary, angular, rather irregular in shape, not round, 0.2- 0.6 mm diam.; disc black, densely brown pruinose; margin prominent, persistent, c. 0.05 mm wide, glossy, black. Hymenium not inspersed. Paraphyses unbranched. Epithecium with black caps. Hypothecium dark brown. Excipulum brown in section. Ascospores 8/ascus, 10-12 × 2.5-3.5 µm, dark brown, smooth, long ellipsoid. Pycnidia not observed.

CHEMISTRY. — Thallus UV-, K-, apothecium disc UV+ green, probably due to an unidentified xanthone (Rf 6 in solvent A[TDA]).

ETYMOLOGY. — Named after the pruinose apothecia.

ECOLOGY AND DISTRIBUTION. — On tree bark in Cerrado forest; only known from Brazil.

Figures

FIG. 3. — Gassicurtia lopesiana sp.nov.,(left) and Gassicurtia pruinosa sp. nov.(right) under 365 nm UV light,A.Aptroot & M.F.Souza 81496. Width of picture 20 mm.

FIG. 4. — Gassicurtia pruinosa sp. nov., holotype, habitus. A, in daylight; B, under 365 nm UV light. Width of pictures 12 mm.