The alliance Bidention tripartitae includes stands of annual wetland species belonging to the genera Bidens, Persicaria, Ranunculus, Rumex and Xanthium. These species are usually 50–150 cm tall and produce large amounts of biomass. They develop on wet, loamy to clayey, nutrient rich substrata. In some places, they replace pioneer vegetation of the class Isoëto-Nano-Juncetea during the course of succession, but often they are the first vegetation type colonizing recently exposed bare wet substrata, especially if they are very rich in nutrients or dry out quickly. This alliance is distributed across Eurasia and North America.