Genomic and morphological data reveal a critically endangered new species from the Atlantic Forest, Paepalanthus salimenae (Eriocaulaceae)

During our investigation of the genetic and morphological variation within the distribution range of Paepalanthus calvus, we observed that specimens from Juiz de Fora municipality, Minas Gerais (Brazil) were morphologically divergent. Through genome-wide analyses using MIG-seq and detailed morphological comparisons, we were able to establish consistent differences between P. calvus and the Juiz de Fora specimens, which supported the recognition of a new species, Paepalanthus salimenae sp. nov. This new species is primarily distinguished by the narrow leaves; trichomes on the leaves, spathes, and scapes; densely pilose involucral bracts; and the tufted apex of some floral organs. Paepalanthus salimenae exhibits low genetic diversity and strong population structure. A preliminary conservation risk assessment suggests this species as Critically Endangered, highlighting the urgent need for conservation efforts to protect its habitat and intraspecific diversity. We provide photographs, line drawings and additional commentaries on the distribution, habitat, and morphological affinities of P. salimenae to congeneric taxa.