Help stop the spread of a new species of Water Chestnut

Localities, pond management personnel and the general public are asked to look for a new species of Water Chestnut (genus Trapa) recently found in the Potomac Watershed. It has been spreading since 1995 so you may have already encountered this floating aquatic vegetation growing over the surface of a pond, lake or other fresh waterbody. This species is identified by the seed cases having two spines instead of four found in the Eurasian Water Chestnut. Reports of this or other invasive aquatic species can be made via a free phone app. Water Chestnut (an annual) will sprout in May 2019, spread over the water surface and then flower and fruit by July, it drops seeds all season until it senesces after a hard frost. To stop the spread, management, by harvesting the plants by mid –July, is very successful in eradicating the plants but it may take several years of effort, if some seeds lay dormant.