Saxicolous lichens in the semi-arid Caatinga in Brazil show substratum shifts Author Aptroot, André Laboratório de Botânica / Liquenologia, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, CEP 79070 - 900, Campo Grande, Mato Grosso do Sul (Brazil) andreaptroot @ gmail. com (corresponding author) Author A, Lidiane Author Santos, lves dos Author E, Marcela Author S, ugenia da Author Cáceres, ilva text Cryptogamie, Mycologie 2021 2021-10-13 20 11 181 189 http://dx.doi.org/10.5252/cryptogamie-mycologie2021v42a11 journal article 247071 10.5252/cryptogamie-mycologie2021v42a11 4286ed17-f7ad-412c-83df-d5280ffe22ef 1776-100X 7815178 Peltula nigrotestudinea Aptroot & M. Cáceres , sp. nov. ( Fig. 3A, B ) Saxicolous Peltula with thallus almost black, consisting of angular, flattened, thick areoles with large interspaces between them. MYCOBANK NO. — MB 839716. GENBANK. — MZ198741 . TYPE . — Brazil , Sergipe , Poço Redondo , Cajueiros , Trilha Ecoparque , 09°39’43”S , 43°40’18”W , on exposed granite, 15.XI.2018 , M. Cáceres & A. Aptroot ( holo- , ISE [ ISE48066 ]; iso- , ABL ). DESCRIPTION Thallus Spreading, covering an area of up to 5 cm diam., c . 0.4 mm thick, containing of areoles with large interspaces between them, closely appressed, almost black; areoles angular, rather irregularly shaped, c . 0.6-1.2 mm diam., flat, marginal areoles not elongated; sides somewhat rounded; attachment area roughly of similar size as upper surface; not distinctly pulvinate or turbinate. Apothecia and pycnidia Not observed. CHEMISTRY. — No secondary substances detected. ECOLOGY AND DISTRIBUTION. — On exposed granite in Caatinga. Known only from Brazil .