INVASIVE! Water Chestnut
Water Chestnut is an invasive species introduced to the US from Asia in the 1800's. It poses a serious ecological threat in the Northeast, where it is becoming more widespread. Once introduced to a body of water it can spread very rapidly; forming dense mats that block sunlight from entering the water. In addition it can make boating and swimming impossible. If left untreated, it can drastically reduce oxygen levels and cause fish kills.
Floating leaves of a single water chestnut plant and the hard "cow-head" chestnut seeds
An untreated infestation of water chestnut that has completely taken over a body of water.
Hydrilla is an invasive aquatic plant introduced to the US from Asia in the 1950's. Similar to other invasive aquatic plants, it has the ability to grow quickly and form dense mats; blocking sunlight and outcompeting other native vegetation.
INVASIVE! Curlyleaf Pondweed
Curlyleaf Pondweed is a non-native invasive plant introduced into the US from Asia in the mid 1800's. It has since been reported in almost every state in the country. It is extremely tolerant of low light and low temperatures, allowing it to easily establish itself as the dominant plant species in a water body. In addition to forming dense mats of vegetation, it also raises phosphorus levels in the water which leads to increased algae blooms.
Often referred to as "pond scum," Duckweed is actually many tiny clover like plants that float near the surface of a body of water. Pond weed occurs in still waters and forms a green coating on the water surface as it spreads; if not treated it will often cover the entire water surface.
Watermeal is another plant, like duckweed, that is commonly referred to as pond scum. It is also a free-floating plant common in still and stagnant water, but is much smaller than duckweed. Watermeal germinates all year round, and can easily cover an entire pond. Duckweed and watermeal are often found growing together on the same waterbody.
Water Lilies are often planted purposely for aesthetic reasons in ponds and lakes; many varieties feature large, colorful flowers when in bloom. As lilies spread they can become problematic in a body of water, with the issues eventually outweighing the aesthetic benefits. Water lilies have sturdy pads and coarse root systems, which can make boating through thick mats of lilies nearly impossible and swimming very unsafe.