Abstract. This article explores the concentration in the global plant molecular life science research output. In the past 15 years, especially the share of articles which refer to the model organism A. thaliana has increased rapidly. Citation analyses show an even greater rise in the importance of this organism. Attempts are discussed to come to a scientometric definition of model organisms. For this purpose a comparison is made with applied microbiology. However, few shared scientometric characteristics were found which could help characterise model organisms. A distinction between major economic organisms and model organisms will therefore continue to rely on qualitative data.