Spotless watermeal

Description:

Rootless duckweed, is a floating freshwater plant, which is the smallest vascular plant on Earth. It is an aquatic plant which grows in quiet water bodies such as ponds. The green part of the plant, the frond, is a sphere measuring about 1 mm wide, but with a flat top that floats at the water's surface. It has a few parallel rows of stomata. There is no root. The plant produces a minute flower fully equipped with one stamen and one pistil. It often multiplies by vegetative reproduction, however, with the rounded part budding off into a new individual. In cooler conditions the plant becomes dormant and sinks to the bed of the water body to overwinter as a turion. The plant is a mixotroph which can produce its own energy by photosynthesis or absorb it from the environment in the form of dissolved carbon. The pictured pot, containing the Wolffia arrhiza plants, was spotted in Tsagarada village, Pelion mountain, Greece.