New crustose lichens from a tropical coastal area in Paraná (Brazil) Author Aptroot, André Author Souza, Maria Fernanda Universidade Federal de Mato Grosso do Sul, Instituto de Biociências, Laboratório de Botânica Liquenologia, Av. Costa e Silva, s / n, 79070 - 900, Campo Grande, MS (Brazil) andreaptroot @ gmail. com (corresponding author) text Cryptogamie, Mycologie 2021 2021-11-10 20 12 191 197 journal article 244475 10.5252/cryptogamie-mycologie2021v42a12 c95fd89d-a9f8-4380-bf52-321cb435a847 1776-100X 7815207 Myriostigma xanthominiatum Aptroot & M.F. Souza , sp. nov. ( Fig. 1 D-F) Corticolous Myriostigma with thallus whitish ochraceous, containing lichexanthone, ascigerous areas delimited, black with orange pruina, ascospores 8/ascus, ellipsoid, hyaline, muriform, c . 12 × 10-septate, 85-94 × 35-39 µm, central lumina much larger ( c . 10 µm diam.) than lumina near the wall. MYCOBANK. — MB839448. TYPE . — Brazil , Paraná , Guaraqueçaba , Tagaçaba Porto da Linha , road PR- 405 km 36.2, at right side of road, in chácara (property of Donald Schause), 14.X.2020 , alt. 15 m , on tree bark, A. Aptroot & M.F. Souza 82089 ( holo- , CGMS ; iso- , ABL ). ADDITIONAL MATERIAL STUDIED. — Same details, M.F. Souza & A. Aptroot 291 ( CGMS ). CHEMISTRY. — Thallus C-, K-, P-, UV+ yellow, with lichexanthone; ascigerous areas K+ red and UV+ red, with an unidentified anthraquinone (Rf 1 TDA, pale orange yellow in acetone solution). DESCRIPTION Thallus corticolous,whitish ochraceous,dull, somewhat granular and variable in thickness up to c . 0.2 mm thick, covering an area of up to 10 cm diam., surrounded by a c . 0.2 mm wide black prothallus line.Algae trentepohlioid, orange, c . 10-15 µm diam. Ascigerous areas delimited, IKI negative, patchy, roundish to irregularly lirelline, black spots with orange pruina, up to 2 mm long and 0.7 mm wide, c . 0.2-0.3 mm high, covering about a quarter of the thallus surface. Asci globose, hyaline, containing 8 ascospores, 100-125 µm diam, wall up to 15 µm thick. Ascospores ellipsoid, hyaline, muriform, c . 12 × 10-septate, 85-94 × 35-39 µm, central lumina much larger ( c . 10 µm diam.) than lumina near the wall. Pycnidia not observed.