Genetic and spatial data on the conservation of the critically endangered Paepalanthus longiciliatus (Eriocaulaceae)

Abstract We provide new genetic and spatial data on the conservation of Paepalanthus longiciliatus (≡ Coracoralina longiciliata (Trovó) Andrino, Eriocaulaceae), a narrowly distributed species from Goiás, Brazil, officially categorized as Critically Endangered (CR). Despite identifying potential occurrence sites surrounding the type locality, which still harbors a population of a few hundred individuals, efforts to locate new populations were unsuccessful. Most of these potential areas are indeed unprotected private properties. Herbarium searches also failed to yield additional specimens; consequently, the species is known only from three records at the type locality (1996, 2009, and 2024). The species occurs in typical dystrophic cambisoils of the Cerrado , with a clayey-silty texture, generally considered less suitable for large-scale monoculture. However, land-use changes observed over time indicate the transformation of native vegetation into a mosaic of diverse uses, including a paved road, monoculture plantations, and pastures, the latter often involving the use of fire and invasive grasses. Genetic data suggest low genetic diversity and high inbreeding, although the relatively high nucleotide diversity suggests that some genetic variation is still retained. These patterns likely reflect the effects of genetic drift in an isolated species restricted to a small population with limited dispersal capacity. The species’ rhizome and sprouting reproduction mode likely explain its survival under moderate adverse conditions. Given these findings, the species should remain categorized as Critically Endangered. Additional botanical explorations, the implementation of a Private Natural Heritage Reserve (RPPN), and ex-situ conservation techniques are essential efforts to ensure the preservation of this species.