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Click here to go back Details of this species in Florida (USA) Status: Alien Invasiveness: Not specified Occurrence: Established Source: NAS, USGS Arrival Date: Introduction: Species Notes for this Location: Management Notes for this Location: Location Notes: Impacts: Ecosystem change: Pennywort is a common native that functionally occupies similar habitats as hyacinth. Differences between pennywort and hyacinth habitats highlight the role of water hyacinth as an invasive "ecosystem engineer". Research specific to hyacinth and pennywort (Hydrocotyle umbellata) in Florida has shown that overall dry biomass of hyacinth is 259% greater than pennywort (Reddy 1984, in Toft 2000). Other research in Florida on hyacinth and a different species of pennywort (Hydrocotyle ranunculodies) has shown that overall dry biomass of hyacinth is 161% greater, and the maximum root length of hyacinth is 164% greater (Jantrarotai 1990, in Toft 2000). The roots of hyacinth can be important habitat for epiphytic macroinvertebrates (aquatic invertebrates living on macrophytes) which illustrates just one of the changes brought about by the invasion of native habitats by water hyacinth (Hutchinson 1967, Schramm et al. 1987, in Toft 2000), especially amphipods (Schramm et al. 1987, Bailey et al. 1993, Bryan 1993, in Toft 2000). Physical disturbance: Boat traffic on several rivers was halted; hundreds of lakes and ponds were covered from shore to shore with up to 200 tons of water hyacinths per acre. Last Modified: 15/08/2003 12:04:06 a.m.