Two new crustose Cladonia species with strepsilin and other new lichens from the Serra de Maracaju, Mato Grosso do Sul, Brazil Author Aptroot, André Author Souza, Maria Fernanda Author Spielmann, Adriano Afonso Laboratório de Botânica / Liquenologia, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Avenida Costa e Silva s / n, Bairro Universitário, CEP 79070 - 900, Campo Grande, Mato Grosso do Sul (Brazil) andreaptroot @ gmail. com (corresponding author) andreaptroot@gmail.com text Cryptogamie, Mycologie 2021 2021-07-02 20 8 137 148 http://dx.doi.org/10.5252/cryptogamie-mycologie2021v42a8 journal article 10.5252/cryptogamie-mycologie2021v42a8 1776-100X 12214676 Trypethelium muriforme Aptroot & M.F. Souza , sp. nov (Fig. 5) MYCOBANK . — MB 83950. DIAGNOSIS . — Corticolous Trypethelium with thallus UV+ yellow and pseudostroma UV-negative, ascospores muriform, 50-70 × 10-13 µm. TYPE . — Brazil . Mato Grosso do Sul , Aquidauana, 2 km SW of Piraputanga, alt. 175 m , 20°29”S, 55°33’17”W , on bark, 27.XI.2019 , A.Aptroot & M.F. Souza 81448 ( holo- , CGMS ; iso- , ABL ). ADDITIONAL MATERIAL STUDIED . — Brazil . Mato Grosso do Sul :Aquidauana, 2 km SW of Piraputanga, alt. 175 m , 20°29’S , 55°33’17”W , on bark, 27.XI.2019 , A.Aptroot & M.F. Souza 81453 ( para- , CGMS ). CHEMISTRY . — Thallus UV+ yellow, K-; pseudostromata UV-. TLC: lichexanthone. ETYMOLOGY . — Named after the muriform ascospores. ECOLOGY AND DISTRIBUTION . — On tree bark in cerrado forest; only known from Brazil . DESCRIPTION Thallus dull, pale olivaceous greenish, with pale whitish patches, not surrounded by a prothallus. Ascomata globose to pyriform, 0.4-0.6 mm diam., single or immersed in pseudostromata, in groups of 2-6. Pseudostroma conspicuous, erumpent to prominent and then constricted, outline roundish to lobate,top convex, sides curved, c. 0.5-2.5 mm diam., initially whitish, later black because the wall becomes exposed, without pigment. Ostioles apical, single, brown to black, 0.2-0.4 mm diam. Hamathecium not inspersed. Ascospores 8/ascus, hyaline, muriform, 9-13 × 1-3-septate, 50-70 × 10-13 µm, fusiform, asymmetrical with the central primary septum well above the middle, markedly constricted at the primary septum with irregularly rounded to ellipsoid lumina of rather different size, not surrounded by a gelatinous sheath. Pycnidia not observed.