Two new and endangered species of Paepalanthus sect. Diphyomene (Eriocaulaceae) from the Brazilian Cerrado

Abstract

Two new species of Paepalanthus (Eriocaulaceae) from the Cerrado hotspot in central Brazil are described and illustrated. Paepalanthus avacanoeiro Trovó & R. Silva-Oliveira sp. nov. occurs in the Chapada dos Veadeiros region, growing on quartzite rocky soils. The species is similar to P. urbanianus, distinguished mainly by being a more robust species with pilose and patent leaves with blackish base and ciliated margin, by its reproductive axis covered by remotely disposed bracts with acuminate apex, and by its inflorescence with fewer scapes. It is currently known from two subpopulations occurring just outside of the local conservation units and is assessed as Critically Endangered (CR). Paepalanthus burle-marxii Trovó sp. nov. is distributed in the vicinities of Brasília, Pirenópolis, Luziânia, and Santo Antônio do Descoberto. It is known from many historical and recent collections inhabiting typical open grasslands, usually over argillaceous-rocky soils. It is distinguished from P. linearis, its most similar species, by its glabrous and wider leaves with membranaceous margin, its narrower capitula with few flowers and dark castaneous involucral bracts, and by the pilosity of the pistillate flower sepals. It is assessed as Vulnerable (VU). Line drawings, photos taken in the field, distribution maps, and comments are provided alongside its conservation status and IUCN red list categories.