What is "comptonia"

Comptonia is a monotypic genus (containing only Comptonia peregrina) in the family Myricaceae, order Fagales. It is native to eastern North America, from southern Quebec south to the extreme north of Georgia, and west to Minnesota. The common name is sweetfern or sweet-fern, a confusing name as it is not a fern.

It is a deciduous shrub, growing to tall. The leaves of the plant are linear to lanceolate, long and broad, with a modified dentate, pinnately lobed margin; they give off a sweet odor, especially when crushed. The flowers are imperfect, meaning that no one flower has both gender parts. It tends to grow on dry sandy sites, and is associated with pine stands.

Comptonia peregrina is used as a food plant by the larvae of some Lepidoptera species, including Bucculatrix paroptila, Grey Pug, Setaceous Hebrew Character, Io moth, and several Coleophora case-bearers: C. comptoniella, C. peregrinaevorella (which feeds exclusively on Comptonia), C. persimplexella, C. pruniella and C. serratella. It is also a non-legume nitrogen fixer.

Several fossil species, such as Comptonia colombiana have been described, showing that the genus once had a much wider distribution throughout the Northern Hemisphere.