In most of the South, a mimosa is either the tree with fluffy pink flowers or a delicious brunch cocktail.
Most of the mimosa trees in the area are some variety or [Albizia julibrissin] or another, but are no longer taxonomically classified as true mimosas. Most of the plants in question are still members of the pea family (your friend Fabacae) though the genus Mimosa is now in its own subfamily.
Thomas Jefferson even [recorded] having A. julibrissin at Monticello, though he called it by another of its common common names: the silk tree. It came to this country via European settlers, and it came to the Europeans via the Florentine nobleman Filippo degli Albizzi. Some of A. julibrissin‘s common names in other countries translate to variations of “night sleeper” and “sleeping tree”, referring to the closing of its leaves at night.
A. julibrissin‘s star feature is the dense clusters of silky, pink flowers throughout summer. The flowers are usually white to pink but have no petals–the color and wispy texture comes from groupings of stamens. The flowers are fragrant and attract butterflies, bees, and other insects.
The plants themselves are about five to twelve meters tall with umbrella-like branches, making it a popular shade tree. The bipinnate leaves are distinctive because of their fine texture and ability to fold themselves closed during the night or rain. The trees are deciduous but provide winter interest with their gently curving branches and prolific fruiting. The seed pods are typical for legumes and look like a skinny pea pod. The pods are edible and sometimes used in livestock feeds.
These days, mimosas are considered an invasive species. The strong root systems have been known to crack and disturb sidewalks and foundations, and is a frequent volunteer along roadside tree borders.