Which plant belongs to the genus Spiraea?

The genus Spiraea encompasses a group of shrubs known commonly for their attractive flowers and varied forms. When considering the given options, the choice of Spiraea spp. is correct because it directly refers to the species that fall under the genus. Spiraea includes numerous species and cultivars that are popular in landscaping for their ornamental value, notably their profuse blooming habits and adaptability.

The other options present different plant types that do not belong to the Spiraea genus. The Common Lilac is classified under the genus Syringa, known for its fragrant flowers. Dwarf Palmetto, or Sabal minor, is a type of palm found in the southeastern United States, while Himalayan Sweetbox, or Sarcococca hookeriana, is a different genus altogether favored for its evergreen foliage and fragrant winter flowers. Thus, Spiraea spp. is the only option that accurately represents a member of the genus Spiraea.