A re-evaluation of the genus Ambrosia (Compositae)

Abstract

In spite of the focus in recent years on the ragweeds and their relatives as sources of allergenic pollen, they are poorly understood biologically and taxonomically.Systematic controversy has centered particularly about the question of the possible congeneric nature of the so-called "true ragweeds," Ambrosia spp., and "false ragweeds," Franseria spp.Linnaeus (1753) established the genus Ambrosia for modern use with the description of four species, Ambrosia trifida, A. elatior, A. artemisiijolia and A. maritima, all of which were based upon earlier descriptions.Cavanilles (1793) established the closely allied genus, Franseria, with the description of the single species F. ambrosioides.The similarity of the two genera was recognized by Cavanilles, as is shown by the specific epithet (ambrosioides) he chose for his species and by a statement in the description that he considered the new genus to be intermediate between the ragweeds [Ambrosia)"Publication number 38 on Atmospheric Pollution by Aeroallergens,