Occurence and variation of calcium oxalate crystals in ten different genera of family araceae

Abstract

Calcium oxalate crystals are the most abundant insoluble mineral found in plants and can be observed in 215 different plant families including gymnosperms and angiosperms. This study was conducted to determine the types and to compare the densities and sizes of the different types of calcium oxalate crystals in the leaves comparing those in the leaf margins and midveins of the ten selected genera of family Araceae. Leaf discs were cleared by using modified clearing method of Coté and Gibernau (2012). Two types of calcium oxalate crystals, i.e., raphides and druses were present in nine genera of aroids, except Typhonium which only had raphides. The densities of raphides and druses vary with genera from 4 - 431 per mm² and 730 - 5401 per mm², respectively. Dieffenbachia had the highest density of raphides both in the leaf margin and midvein while the Dieffenbachia and Philodendron had the highest densities of druses in the leaf margin and midvein, respectively. The sizes of raphides and druses also vary from each of the genera from 47.4 μm - 175.07 um and 14.26 μm - 45.67 μm, respectively. Dieffenbachia and Anthurium had the longest raphide crystals and largest druses, respectively, while Typhonium and Colocasia had the shortest raphides and smallest druses, respectively.