Ramey (2001) states that H. polysperma is a fast-growing and fast-spreading invasive that can out shade other submersed plants. It can also occupy the entire water column. This species has many adventitious roots at stem nodes, which means that broken off fragments can easily grow. H. polysperma clogs irrigation and flood-control canals, and mats of fragments can collect at culverts and interfere with water control pumping stations. This species also interferes with navigation of the waters it invades. H. polysperma also competes with another aggressive non-native invasive plant, Hydrilla verticillata. Doyle et al. adds that, "The weed potential of the species appears high and related to several growth characteristics including multiple growth forms (Botts et al. 1990, in Doyle et al. 2003), the ability to produce a high biomass, and the ability to form a dense canopy at the water-air interface (Spencer and Bowes, 1985, in Doyle et al. 2003)."
No Impact information recorded for Hygrophila polysperma