Occurrence of calcium oxalate in different ornamental plant species

Abstract

A plant is defined as toxic once it is inserted into the human or animal organism, when it is capable of causing effects that induce damage to health. The presence of calcium oxalate crystals in the organs of the plant represents a fundamental aspect for the characterization of the plant as toxic, due to the fact that it is one of the active principles that cause intoxication. The objective of this work was to identify the species that present this substance and thus contribute to the knowledge of the variety of potentially toxic plants. After obtaining and disclosing scientific results, it is expected to minimize the accidental intoxication rates, due to the lack of knowledge about plants with toxicological potential. The work was directed especially to ornamental species found in environments with intense flow of people, such as squares, school gardens, nurseries and residences that had plants facing the public roads. The method used consisted of collecting samples directly at the sites and performing the histological analysis of the material collected in the laboratory. Free hand histological sections were specially made from the stem and petiole of the plant for the assembly of slides that were later observed under an optical microscope and recorded by photomicrographs. The results indicated the presence of calcium oxalate in 77% of the 30 species analyzed, mainly in the form of raphides and drusen.