A Brief Review of Recent Controversies in the Taxonomy and Nomenclature of sensu lato.

The genus is widespread and morphologically difficult, and as a result, no taxonomic treatment to date has been entirely satisfactory. The only modern revision, by Bolli, reduced the number of recognized species worldwide from over 30 to nine. In Bolli's treatment, five taxa formerly considered to be distinct species, including , , , and the endemic island taxa and , were placed within as subspecies. Available data relating to these taxa are briefly reviewed. It is suggested that, while the recognition of the American elder as subsp. is reasonable, and possibly would be better treated as distinct species; the best classification of the other two taxa remains uncertain. The preferred family assignment for is , though the name of this family may change in future depending upon the ultimate disposition of published nomenclatural proposals now in process.