Estudio palinológico de las Licofitas (Lycopodiopsida) de las Sierras Pampeanas centrales de Argentina

Background and aims: The Sierras Pampeanas Centrales of Argentina constitute the fourth centre of diversity of lycophytes and ferns in the Cono Sur, where representatives of four families of lycophytes live: Huperziaceae, Lycopodiaceae, Isoetaceae and Selaginellaceae. The aim of this work is to provide data of the morphology of their spores observed with optical and scanning electron microscopes, as a contribution to the taxonomy and conservation. M&M: The materials were analysed without prior chemical treatment and photographic records were obtained with both observation equipments. Results: The morphological diagnostic features of the spores are presented. The Huperziaceae and Lycopodiaceae are isosporous with trilete spores. Huperziaceae presents foveolated or fossulated spores, while Lycopodiaceae spores are reticulate, scabrate and baculate. In Isoetes hieronymi (heterosporate), the microspores are monolete with echinate ornamentation, while the megaspores are trilete, with reticulate ornamentation. The Selaginellaceae, all heterosporate, produce trilete microspores and megaspores, both with varied ornamentation. Conclusions: Spore characteristics provide relevant information for regional floristic studies as well as for taxonomic assignments, both of extant flora and fossil records. Also, for studies of the composition of soil spore banks as a tool for the conservation of local floristic biodiversity.