Most beginners are introduced to plant diversity through identification keys, which develop differentiation skills but not species memorisation. We propose that mnemonics, memorable "name clues" linking a species name with morphological characters, are a complementary learning tool for promoting species memorisation. In the first of two experiments, 64 adults in a group-learning environment were taught species identification using mnemonics, an educational card game and a text-based dichotomous key. In the second experiment, 43 adults in a self-directed learning environment were taught species identification using mnemonics and a pictorial dichotomous key. In both experiments, mnemonics produced the highest retention rates of species identification based on vegetative characters. The educational value of these findings is discussed for vegetative plant identification and broader applications.