Abstract

• Rotheca serrata (L.) Steane & Mabb. (Family Lamiaceae) is an important medicinal plant growing in the tropical and warm temperate regions. This plant is locally known as Yin-bya in Myanmar. It was collected from Hpa-an University Campus, Hpa-an Township, Kayin State from March to September 2019. The flowering and fruiting period is from May to September. In morphological study, the plant is perennial shrub, stem bluntly quadrangular. Leaves opposite and decussate, sharply serrate margin. Flower numerous, showy, dichotomous cymes. Fruits black in mature, seeds pyrene. In histological characters, diacytic stomata, uniseriate glandular and non glandular trichomes were present. Calcium oxalate crystals were present in mesophyll tissue of lamina and acicular crystals in petiole and stem. The vascular bundles were collateral and close type in the midrib, collateral and open type in petiole and stem. The present of alkaloid, flavonoid, phenolic compound, starch, reducing sugar, glycoside, saponin, tannins, α-amino acid and carbohydrates were found in phytochemical investigation. In physicochemical properties, the solubility of powdered leaves was found to be most soluble in polar solvent.