Structural Characterization of Some Medicinal Weeds (Portulaca oleracea, Melissa officinalis and Peperomia pellucida) at Rivers State University

Background and Objectives: Melissa officinalis is a member of Lamiaceae family that is said to possess antifungal and antiviral properties, while Peperomia pellucida belongs to the family Piperaceae and is found in most African countries which can be used to reduce glucose and uric acid levels. Lastly, Portulaca oleracea is an annual plant that belongs to the family Portulacaceae which is used as a common vegetable. This study investigated the anatomical and histochemical structures of the stem and petiole of Melissa officinalis L. (lemon balm) Peperomia pellucida L. (pepper elder) and Portulaca oleracea L. (common purslane) in Rivers State University. This investigation aimed toprovide basic anatomical and histochemical data that will characterize and distinguish among the three species. Materials and Methods: Plant materials were identified, collected and fixed in formaldehyde: Acetic acid and alcohol (FAA) solution for three days. The hand-sectioning method was employed for both studies, in addition to the application of hydrogen peroxide and silver nitrate for 30 min in the histochemical study. Results: The anatomical structures are relatable due to their similarities in the layer of the epidermis and vascular bundles. The histochemical results showed that they possess calcium oxalate crystals apart from Peperomia pellucida . Conclusion: The standardized anatomical characters assisted in the detection and diagnosis of particular medicinal plant species.