CONICET | Buscador de Institutos y Recursos Humanos

ABSTRACT The Saltgrasses are pioneer plants in the early stages of succession in salinesoils and constitute particular zonal communities of low species variability. Phytolithassemblage analysis of these species allows a community type to be characterized thatconsists mainly of species with well-defined environmental adaptations, which aresignificant because of their paleoecological importance. The aim of the present study is tocharacterize phytolith assemblages of Distichlis species in South America, emphasizingtheir leaf morphotypes. Four Distichlis species, mainly of South American distribution, andfour chloridoids species from different clades of the subfamily (Lycurus, Eragrostis,Muhlenbergia and Sporobolus) were selected for this study. The phytoliths were obtainedfollowing Labouriau?s calcination technique. Quantitative analysis of the morphotypeabundance in the phytolith assemblages studied allowed the three main groups to bedistinguished, with the common presence of multicellular phytoliths with long, short,bulliform and subepidermal silicified cells, as well as unicellular phytoliths, such as shortnarrow saddle, prickles and hairs, polyhedral and long elongate types. Conversely, theexclusive presence of horned towers, short truncated cones, circular/ovoid, papillaetrichome, silicified microhairs, and isolated and articulated irregular epidermal cellphytoliths in Monanthochloinae clade species distinguishes them from the Muhlenbergiinaeclade species with square/rectangular and subrectangular saddles and acute dumbbells.Eragrostis and Sporobolus species have shown some particular morphotypes (such as hairswith cushions, long truncate cones, dumbbell and dumbbell/saddle). The results not onlyallowed us to identify the Distichlis species, but also to distinguish them from othergrasses, including those in their subfamily.