The name of several plants of the genus Spiræa, especially the white- or pink-flowered Spiræa salicifolia, a low European and American shrub, and the herbaceous Spiræa Ulmaria, which has fragrant white flowers in compound cymes. [1913 Webster]
meadowsweet, n.
1 a rosaceous plant, Filipendula ulmaria, common in meadows and damp places, with creamy-white fragrant flowers.
2 any of several rosaceous plants of the genus Spiraea, native to N. America.