Gassicurtia lopesiana 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 : 173-177

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

( Figs 2 , 3 )

Corticolous Gassicurtia similar to G. rufofuscescens (Vain.) Marbach , but differing by the thallus UV+ yellow due to lichexanthone, apothecia similarly with red anthraquinone in the excipulum, ascospores 10-12 × 2.5-3.5 µm.

MYCOBANK. — MB 839653.

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, M.F.Souza & A.Aptroot 13 (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. 0.2 mm wide, black hyphal prothallus line. Isidia and soredia absent. Apothecia sessile, solitary, 0.2-0.6 mm diam.; disc black, not pruinose; margin prominent, persistent, c. 0.05 mm wide, glossy, dark brown to vermillion red. Hymenium not inspersed. Paraphyses unbranched. Epithecium with black caps. Hypothecium dark brown.Excipulum bright red in section. Ascospores 8/ascus, 10-12 × 2.5-3.5 µm, dark brown, smooth, long ellipsoid. Pycnidia not observed.

CHEMISTRY. — Thallus UV+ yellow, K-; ascomata inside K+ red. With anthraquinone and lichexanthone.

ETYMOLOGY. — Named after the grandmother of Fernanda, Maria Lopes de Souza, in recognition of her constant support to Fernanda’s studies.

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

DISCUSSION

The new species is close to Gassicurtia catasema (Tuck.) Marbach , which up to recently ( Santos Andrade et al. 2020). It shares the presence of lichexanthone, but differs by the red pigment inside the apothecium margin. In the key to Brazilian species of Gassicurtia by Santos Andrade et al. (2020) it would key out at couplet 5a, differing from G. rufofuscenscens by the thallus UV+ yellow due to the presence of lichexanthone. It grows side-by-side with the next species.

Figures

FIG. 2. — Gassicurtia lopesianasp.nov., holotype,habitus.Width of picture 15 mm.

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.