This paper is the second in a series treating the Amaranthaceae s.l. in South America. We present here a taxonomic revision of tribes Salicornieae and Suaedeae (subfamily Salicornioideae) based on the study of herbarium material, type specimens, digital images, original publications, and field observations. The South American Amaranthaceae s.l. flora includes Allenrolfea Kuntze, Heterostachys Ung.-Sternb., Mangleticornia P. W. Ball, G. Kadereit & Cornejo, and Salicornia L. from Salicornieae, and Suaeda Forssk. ex J. F. Gmel. from Suaedeae. Lectotypes for seven names are here designated. The distribution of all species is updated based on the revision and proper identification of many herbarium specimens and field observations. A new synonym for Salicornia neei Lag. is here proposed.