The distribution of Ageratina altissima (L.) R. M. King & H. Rob. in Austria

I report on the distribution of White snakeroot (Ageratina altissima) (Asteraceae, Magnoliopsida) in Austria.The first established occurrence of this species in Austria was recorded in Lower Austria in 2006.Here, I summarize the current distribution of the study species at this locality.In 2006, the species had invaded several 100 m 2 .In 2024, it has spread over c. 2.7 ha forming open to dense stands.The composition of the invaded vegetation was documented by four plots.Ageratina altissima invades mesic to temporarily wet tall herb vegetation in forest clearcuts, forest fringes, open conifer plantations, and broadleaved forests.Thus, given the substantial expansion in the last two decades, I suggest that the future spread of Ageratina altissima should be monitored, and if necessary, management actions should be taken.