The presence or absence of micro-characters in plant system like calcium oxalate crystals has been used for understanding the evolutionary relationships of plant species. The size and appearance of calcium oxalate crystals (COC) can differ within families, genus, and species and these characteristics might be genetically
controlled. We have studied the calcium oxalate crystals in the different plant parts (leaves, stems, petiole, corm, and root) of some selected species belonging to the family Araceae. The selected plants belonged to different habitats like marshy, semi aquatic, terrestrial and were mostly herbs, shrubs, and climbers. Among
the selected species, two species are edible and economically important. Edibility of petiole, leaves, stems and corms depends upon the frequency and intensity of the calcium oxalate crystals. Two types of crystals were observed which were mostly species specific. The frequency of crystals is probably related with the habit, habitat and also the environmental conditions.