Alien weed Xanthium spinosum in Slovakia I: distribution and habitats

Abstract

Xanthium spinosum is a naturalized neophyte of agricultural land, its distribution and habitats have not yet been studied in detail in Slovakia. The aim of the work was to collect all floristic data of this weed species, to present its current and historical distribution, and to characterize its typical habitats in Slovakia. As shown in analysis, Xanthium spinosum occurs mainly in the Pannonian region; in the Carpathians it was more frequent only in the 19th century and in connection with the transport of diaspores by sheep wool. The number of localities increased gradually until the 1970s, but then fell sharply due to the intensification of agriculture. Consequently, it is currently not considered to be a significant weed in Slovakia. X. spinosum mostly occupies open and sunny ruderal habitats (road edges, manure pits, field roads, abandoned fields and places) and especially pastures, rarely river banks. Both in the past and today, the species rarely occurs in fields.

Keywords

• central europe
• neophytes
• occurrence
• spreading