The genus <i>Sesuvium</i> (Aizoaceae, Sesuvioideae) in the Southern Cone

Abstract Sesuvium is a genus of 14 to 17 species succulent plants, both annual and perennial, widely distributed in tropical subtropical regions. The has not yet been studied detail the Southern Cone (Argentina, Brazil, Chile, Paraguay Uruguay), which led misidentification numerous specimens as S. portulacastrum . As part ongoing floristic, taxonomic ecologic studies Argentina, we revise for Cone. This study based on field investigation, examination herbarium specimens, revision literature. treatments, maps distribution, detailed descriptions, photographs, an illustration, dichotomous key comparative table differentiate occurring are presented. Finally, ecological, morphological, aspects discussed. new combination S americanum (≡ Trianthema Gillies ex Arn.; = verrucosum Raf.) proposed. Lectotypes three names here designated ( revolutifolium Vahl Willd.; Lam., parviflorum DC.). Four should be accepted Cone: , humifusum mezianum sessile Furthermore, excluded from flora