Eight new species of Pyrenulaceae from the Neotropics, with a key to 3-septate Pyrgillus species

Abstract

AbstractEight new species of Pyrenulaceae are described as new to science from Brazil, Guyana and Puerto Rico. Pyrenula sanguineomeandrata Aptroot & Mercado Diaz (with a thallus with red, KOH+ purple pigmentation of lines or a reticulum, simple ascomata with vertical ostioles, a deep red inspersed, KOH+ orange hamathecium, and dark brown 3-septate ascospores 25–29×10–12 μm) and P. sanguineostiolata Aptroot & Mercado Diaz (with a thallus with deeply immersed simple ascomata with vertical ostioles, which are superficial and bright red, and 3-septate ascospores 25–28×9–12 μm) are described from submontane evergreen forests in Puerto Rico. Pyrenula biseptata Aptroot & M. Cáceres (with simple ascomata with vertical ostioles, an inspersed hamathecium and 2-septate ascospores 11–12×4·5–5·0 μm) and P. xanthinspersa Aptroot & M. Cáceres (with an ecorticate thallus containing lichexanthone, simple ascomata with vertical ostioles, not inspersed hamathecium and 3-septate ascospores 14–17×6·0–7·5 μm) are described from rainforest in Amazonian Brazil. Pyrenula subvariabilis Aptroot & Sipman (with fused ascomata with lateral ostioles and submuriform ascospores 17–20(–25)×6–9 μm) and Sulcopyrenula biseriata Aptroot & Sipman (with a thallus containing lichexanthone, simple ascomata with lateral ostioles and lozenge-shaped ascospores with 8 locules, (13–)15–17(–20)×8–10 (width)×6–7 (thickness) μm) are described from savannahs in Guyana. Special attention is paid to the genus Pyrgillus: two new species from the 3-septate core group of this small genus are described from Brazil, viz. P. aurantiacus Aptroot & M. Cáceres (with a corticate thallus containing lichexanthone, mazaedium with orange, KOH+ violet, UV+ red pruina and ascospores of 13–16×6·0–7·5 μm) and P. rufus Aptroot & M. Cáceres (with a corticate thallus containing lichexanthone, mazaedium with dark red, KOH+ orange, UV+ red pruina and ascospores of 15·0–17·5×5·0–6·5 μm). An updated key to the 3-septate species of Pyrgillus is provided.