Morphological descriptions of Holocene palynomorphs from a fragment of the “Savana Estépica Parque” in Barra do Quaraí, Rio Grande do Sul, Brazil

Abstract

Despite its relatively small area in westernmost portion of Rio Grande do Sul, the “Savana Estepica Parque” constitutes a single unit in the phytogeography of the State, lacking research on its floristic and vegetation histories. A total of 86 samples from a sedimentary profile (30º 16’27.9”S and 57º 26’33.6” W) with a basal age of 7,660 ¹⁴C years BP, and 15 surface samples were collected from this vegetational formation, in Barra do Quaraí Municipality, for palynological analysis. In this paper, descriptions and illustrations of 97 palynomorphs are presented (10 fungi, four algae, two bryophytes, six ferns, one gymnosperm, 73 angiosperms and one zooclast) including genus and species that characterizes the “Savana Estépica Parque” vegetation, such as Aspidosperma quebracho-blanco Schltdl., Parkinsonia aculeata L., Prosopis L., Tillandsia L. and Vachellia caven (Molina) Seigler & Ebinger, besides the macrophyte Lemna L., which description is unknown for the Latin America.