Floating Bladderwort vs Inflated Bladderwort

One of the less common forms of bladderwort in Conway Lake is Floating Bladderwort (Utricularia radiata). It is easily spotted by radiating spokes of floating leaves that help keep the yellow flowering stem above the surface of the water (see photo below from Pennacook Cove). Floating Bladderwort is a native plant but there is an invasive bladderwort that is nearly identical and beginning to appear in NE lakes - it is Inflated (or swollen) Bladderwort (Utricularia inflata). The two look nearly identical but the Inflated Bladderwort is larger and the inflated spokes narrow towards the flowering stem. Inflated Bladderwort can be a problem, becoming dominant in ponds/lakes and displacing other native aquatic plants.

Amy Smagula reports that Inflated Bladderwort is not being managed by the state but they recognize it as a non-native and are monitoring it presence in NH lakes. Its worth keeping an eye out for plants that look like this in Conway Lake, especially if they begin to occur in large numbers.

Floating bladderwort in Pennacook Cove - grid 418.