<p>Crystallisation is a common phenomenon in plants. In Angiosperms, the family Araceae abundantly contains calcium oxalate crystals (CaOx), which typically form within parenchyma or aerenchyma cells as idioblasts. These idioblasts produce a range of crystal types, including crystal sand, prismatic crystals, pyramidal crystals, druses, and raphides. Our study focuses on the micromorphology of druses and raphides. Druse exhibits long-height prismatic crystals with tapering ends and short-height prismatic crystals with sword-like ends. Raphides have distinct bridge positions, including centred, sub-centred and not-centred; groove positions, including on the upper and lateral surfaces; while the raphide termination are of five different morphological types, including short wedge-shaped continuous (SWC), short wedge-shaped protruding square (SWP1), short wedge-shaped protruding inflected (SWP2), thicker tapered type (ThTT), and thinner tapered type (TnTT). Based on this micromorphology, a dendrogram was created using the UPGMA algorithm to explore taxonomic relationships across 16 genera and 20 species. The resulting dendrogram comprises six clusters. These cluster was interpreted by node point (NP) and NP is represented by coefficient values (CV), where lower values (~ 0.51) indicate less similarity and higher values (~ 0.93) indicate closer similarity. Among the clusters, Cluster 6 derive from Node Point-A (CV ~ 0.51), indicating less similarity (early divergence) from the other clusters, while Clusters 1–5 originated from NP-B2 (CV ~ 0.83), NP-B1.2.2 (CV ~ 0.83), NP-B1.2.1 (CV ~ 0.78) and NP-B1.1.2 (CV ~ 0.83), respectively, each comprising different species in distinct sublineages, with each lineage representing a single species. Therefore, evidence from the dendrogram concluded that the crystal’s micro-morphology is the most significant and taxonomically powerful feature for distinguishing both genus and species levels.</p>