One of the fundamental components of science education in Thailand and other regions is the study of plant diversity. Nevertheless, students' lack of interest in this topic may be due to its overwhelming content and the perceived disconnection to their daily lives. To address this issue, an educational card game that incorporates concepts of plant taxonomy, distinctive characteristics, phylum, and several examples of local plants was developed to provide a more engaging, relevant, and conceptually appropriate approach to learning. An investigation of students' conceptual understanding before and after playing the card game, as well as their motivation towards the intrinsic value of the learning, was undertaken to assess the efficacy of the developed card game. The results of the study revealed that students' participation in the activity led to an increase in conceptual knowledge and a heightened degree of internalisation in motivation. As such, it is recommended that teachers incorporate the use of this educational card game in their curriculum to enhance students' understanding and appreciation of the topic of plant diversity.