Mimosa is a small plant with leaves like those of the pea family. But you also have Mimosa trees which are usually small trees except for the Silk Tree that grows fairly large and tall.

A mimosa tree in bloom.

 

Mimosa is a species of acacia, and as you can see from their pea-like leaves, acacias belong to the Leguminosae orpea family of plants. Acacias are famous for growing in tough environments, and the family includes the thorn trees of the African savannah and the wattles of the Australian bush. Wattle flowers have lots of stamens, so they often look like small bottle brushes or pompons. Mimosa originally comes from Australia, where it is called the Silver wattle (Acacia dealbata) from the silvery-green colors of its leaves. Some Silver wattle trees were taken to the Mediterranean area in the early 19th century, and they managed to adapt to the colder climate. Now, the masses of bright-yellow flowers signal the end of winter in southern France. In Japan, you can see mimosa trees growing in small city gardens, or even as street trees, while florists sell branches of the cut flowers by the French name of Mimosa. The flowers have a pleasant, almond-like fragrance.

The Japan Times: March 1, 2006