&i;Flora of North America, Volume 4,&o; will be the second volume of nineteen on dicotyledons to be published in the &i;Flora of North America&o; series. It treats 892 species in 124 genera and ten families (Phytolaccaceae, Achatocarpaceae, Nyctaginaceae, Aizoaceae, Cactaceae, Chenopodiaceae, Amaranthaceae, Portulacaceae, Basellaceae, and Molluginaceae ). Each of the included species is illustrated with a line drawing that, in combination with the key and descriptions, will facilitate identification of this economically important group of plants.