Onderzoek naar plantengeografische aspecten van adventieve plantesoorten in Nederland

A (well labeled) herbarium specimen can give information about the locality and the habitat of the plant, the year, month and even the day of find, the stage of development in the life-cycle and perhaps the method of seed dispersal. The author has collected data of several adventitious species which frequently occur in the Netherlands but have not yet naturalized. By adding information out of the literature about the life-cycle, locality, period of flowering and the habitat of the original area he hopes to create in the near future a series of 'adventitious portraits'. Analysis of these portraits may provide the answer to the question of why rather common plants, with sometimes more than a hundred records in Holland, are still adventitious. This information may result in new criteria for the naturalization of originally adventitious species.