The Worldwide Spread, Success, and Impact of Ragweed ( Ambrosia spp.)

The Ambrosia species represent one of the most problematic groups of invasive weeds around the world. The ease with which they are introduced and spread in new countries, their generalist ecological requirements, and functional traits facilitate their invasion and subsequent naturalization in new areas. All of these aspects contribute to increasing their global social and economic impact, which is mostly related to pollen allergy. Here we analyze available scientific publications about Ambrosia artemisiifolia, A. psilostachya, A. tenuifolia, and A. trifida, with the aim of defining the current level of knowledge and summarizing important data that are currently scattered throughout the literature. Specifically, we analyzed the following: (1) their current global distribution and current stage of invasion; (2) traits and requirements promoting their introduction, reproductive success, and adaptation to climate and environment in the nonnative range; as well as (3) current knowledge about allergens and elements increasing their impact.