For plant identification in school biology, many digital and analogue identification methods have been developed to make this demanding and little motivating process more student-orientated. In this experimental field study, we examine two empirically developed tools: the digital identification app "ID-Logics' and the paper-based key, generated by the online platform 'Eikes Baumschule'. In line with Self-Determination Theory (SDT), an evaluation study with 251 students was conducted to investigate the effect of both tools on students' intrinsic motivation. The results of the study were unexpected, as the different media regarding the SDT did not present themselves as projected: While both tools influence students' intrinsic motivation positively, each displays specific effects regarding enjoyment, perceived competence, and perceived autonomy. Taking these effects into account, each tool under investigation offers different advantages and disadvantages for plant identification in the field. The resulting opportunities and challenges, for plant identification, of both tools are discussed critically against the background of SDT, and future directions for research on intrinsic motivation in the context of species identification are mapped. Furthermore, this study shed light on the process of species identification and thus indicates recommendations for practical use in biology lessons.