Taxonomic revision of the Paepalanthus trichophyllus complex (Poales, Eriocaulaceae) with the description of two new species

We revise the Paepalanthus trichophyllus species complex using multivariate morphological analyses, leading to a redefinition of species boundaries, clarification of nomenclature and taxonomy, and the description of two new species: P. linearilaminatus L.E.F.Silva sp. nov. and P. rollimae L.E.F.Silva sp. nov. Paepalanthus trichophyllus is now circumscribed as occurring in south-western Minas Gerais and south-eastern Goiás. Despite this narrower range, the species continues to exhibit substantial morphological variability, particularly in floral structures and stem morphology. For P. trichophyllus, we provide a second-step lectotype and a new synonym (P. canescens f. angustifolia). The new species P. linearilaminatus occurs in the center to south of Bahia and is mainly distinguished by its linear leaves and oblanceolate floral bracts, while P. rollimae occurs in Chapada dos Veadeiros National Park and its surroundings in Goiás, being mostly characterized by its elliptical or elliptical-lanceolate leaf blades, rounded spathe apices, and discoid capitula. The geographical isolation and consistent morphological traits of P. linearilaminatus and P. rollimae support their recognition as distinct species. This study contributes to the taxonomic understanding of Paepalanthus diversity in Brazil and highlights the rich biodiversity of the Cerrado domain.