Título:	Grindelia rheophila (Asteraceae, Astereae): a new species and a river-borne exception in a genus shaped by Deserts.
Autor:	FERNANDES, F. BÜNEKER, H. M. IGANCI, J. SOUZA-CHIES, T. T. de HEIDEN, G.
Afiliación:	FERNANDO FERNANDES, UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL; HENRIQUE MALLMANN BÜNEKER, UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL; JOÃO IGANCI, UNIVERSIDADE FEDERAL DE PELOTAS; TATIANA TEIXEIRA DE SOUZA-CHIES, UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL; GUSTAVO HEIDEN, CPACT.
Año:	2025
Referencia:	Phytotaxa, v. 720, p. 35-45, 2025.
Descripción:	Abstract: Grindelia rheophila (Asteraceae, Astereae), the first known rheophytic gumweed species is proposed, described, and illustrated here. Unlike most species of the genus, which are adapted to almost permanently dry environments, this new species thrives in dynamic riverine habitats with fast-flowing water. Grindelia rheophila is characterized by the erect to decumbent growth form, long linear-elliptic leaves, and a pappus with hemipaleaceous and bristle elements, which differentiate it from the morphologically similar G. buphthalmoides, G. pulchella and G. scorzonerifolia. The new species is known only at the northern headwaters of the Ibicuí river basin along the edge of the South Brazilian plateau in the state of Rio Grande do Sul, Brazil, where it grows along rocky flood-prone margins of the watercourse, as rapids and waterfalls are influenced by seasonal hydrological fluctuations. We highlight the vulnerability of rheophile ecosystems to anthropogenic threats, particularly dam construction and climate-driven extreme weather events, justifying the recognition of the new species as Critically Endangered (CR A2ac+3c+4ac; B1a,b(i,ii,iii,iv),c(iii)). A watercolor illustration, habitat photographs, a distribution map, and an identification key for Brazilian Grindelia are also provided.
Thesagro:	Taxonomia Vegetal Conservação Planta Compositae
NAL Thesaurus:	Machaeranthera Plant taxonomy
Palabras clave:	Endemismo Reófitas Plant conservation Rheophytes
Tipo de Material:	Artigo de periódico
Acceso:	openAccess
Aparece en las colecciones:	Artigo em periódico indexado (CPACT)