A Hobbit of the Shire, who married into the Baggins family three generations before Frodo's time. Her husband was Ponto Baggins, and through Ponto's brothers Mimosa was indirectly related to both Bilbo Baggins and Frodo. She had two children of her own. The elder, Rosa Baggins, married into the Took clan, and through her Mimosa was the ancestor of both Merry Brandybuck and Pippin Took. Her younger child was a son named Polo, who also had many descendants, including various Bagginses, Bolgers and Burrowses.
Mimosa is a a genus of plants (trees, shrubs and herbs) of the legume family. The name refers to their ability to react and move, mimicking animals.