Catalogue of neophytes in Belgium (1800-2005).
A catalogue of Belgian neophytes has been compiled for the first time on the basis of a thorough and critical revision of the main Belgian herbaria. All non-native vascular plant species, recorded in Belgium since 1800, are included regardless of their degree of naturalization. This amounts to a total of 1,969 taxa. For each taxon the following data are provided: scientific name, synonym, family, accidental versus deliberate introduction, dates of the first and most recent collections/records, native geographic area, presence or absence in Flanders, Brussels Capital Region and Wallonia, degree of naturalization and means of introduction. At least 75% of the introductions remains strictly casual. Among the naturalized and/or invasive taxa the proportion of deliberate introductions is ca. 60%.