As part of the ongoing study of some genera of Caryophyllaceae and the preparation of their treatments for the new edition of the Flora of Argentina, notes about some members of this family are presented. Two species (Petrorhagia prolifera and Scleranthus polycarpos) are reported for the first time for the Flora of Argentina. Sixteen names are here lectotypified: Arenaria achalensis, A. alsinoides, A. andicola, A. bisculca, A. lanuginosa var. diffusa, A. lanuginosa var. ensifolia, A. lanuginosa var. megalantha, A. palustris, A. patagonica, A. serpens var. robusta, A. serpens var. humilior, Philippiella patagonica, Sagina apetala var. melanopotamica, S. apetala var. paludosa, Spergula humifusa, and Spergulastrum lanuginosum; one neotype is also designated for Saponaria hispanica. One nomenclatural change (Arenaria serpens var. humilior comb. nov.) is proposed.