They are the smallest flowering plants known to the genus Wolffia, being less than 1.5 mm in size. They are commonly found in still or sluggish waters, forming large floating mats. Duckweed is a tiny green plant with shoe-shaped leaves, each plant has two to several leaves joined at the base and a single root hangs beneath. The flowers of duckweed bloom between late June and early August, these flowers are often referred to as minute flowers. Duckweed is and important food source to ducks, geese, pheasants, muskrats, and beaver among other organisms.
Salvinia plants are floating ferns, there are only ten species in the world.
They inhabit still waters rich in organic content . The water ferns have joined oval leaves . Their leaf surfaces are covered with stiff hairs. They have root-like structures which are modified fronds. As an economical use, some water ferns are being considered as a source of livestock feed,to their native South America, however since these plants contain high amounts of lignin and tannins they are devalued as a product.