<P> Duckweeds of the genus Wolffia are the world's smallest flowering plants . Fully grown, they measure only 300 μm by 600 μm and reach a mass of just 150 μg . </P> <P> Nanobes are thought by some scientists to be the smallest known organisms about one tenth the size of the smallest known bacteria . Nanobes, tiny filamental structures first found in some rocks and sediments, were first described in 1996 by Philippa Uwins of the University of Queensland . </P>

What is the smallest living thing in the world