Dec. 4, 2019

European frog's-bit, Hydrocharis morsus-ranae

Here we go again with the invasive deal. Frog'-bit was planted in ponds at the Central Experimental Farm Arboretum in Ottawa in 1932. It escaped from there, and was seen in nearby waters by 1938. By 1974 it had reached the U. S. in New York, and in 1996 was found in Michigan. It can rapidly spread wherever it appears, choking waterways. Frog's-bit develops late season buds at the ends of underwater shoots. These buds, called turions, drop off late in the season. They have the remarkable ability to sink to the bottom of the water as it cools in the winter, then rise again in the spring. Much like seeds, they store nutrients, and generate new plants. Some of our native genera like bladderworts and water milfoils also develop turions. The name frog's-bit may come from the plentiful late shoots that look like they could entangle frogs. European frog's-bit has now been reported from MI, NY, ON, and QC. It is endangered in Switzerland. Monroe Co MI, 8/2/11.