10 genera and 232 species are recognized within the Polystachyinae. Polystachya, with 196 species, is the largest genus of the subtribe and 13 sections are recognized within it. A synopsis of the subtribe is provided. Comprehensive descriptions, full synonymy, illustration of flower parts, distribution maps, detailed ecological, phenological and distribution data are provided for each taxon treated and a list of 5480 examined specimens from the whole range of of distribution of the subtribe were analysed in detail. Keys to the genera, species of particular genera, sections and subsections and regional keys for the Asian, American and African species of Polystachya. Two new species, five new sections and six new subsections are described, plus two new combinations.