Abstract
Based on specimens from twenty-one herbaria from China and USA, as well as observations using SEM, the genus Botrydium is resurrected as Neobotrydium. It has a number of distinctive characters: the plants are covered with granular hairs and granulated globular gland-grains, strong smell, and dichasia. Neobotrydium is removed from Chenopodium. The differences between Neobotrydium and Chenopodium, as well as circumscriptions of five glandular genera, Neobotrydium, Cycloloma, Roubieva, Ambrina, and Dysphania are discussed. Neobotrydium comprises twenty species which occur in Asia, Europe, North Africa, North America to Northwest of South America and Australia. Four new species are described: Neobotrydium corniculatum and Neobotrydium ornithopodum from China, Neobotrydium peruensis from South America, and Neobotrydium burundiensis from Africa. A diagnostic key is presented.