Comparative study on morpho-anatomy of leaf, stem and root of Boerhaavia diffusa L. (Nyctaginaceae) and its adulterant plants

Abstract

Punarnava (Boerhaavia diffusa L.- Nyctaginaceae) is a promising drug to rejuvenate new cells in the body. It is well known in Ayurvedic medicine and locally called Tambadivasu. Superficially it is similar to other species of Boerhaavia and species of Trianthema and Sesuvium. Due to the minute morphological differences, the above plants are erroneously used in medicine as Punarnava, and at times on purpose as an adulterant. Therefore, it is necessary to highlight the anatomical features of Punarnava for proper identification of the medicinal plant species for local people and for scientific research. Due to the ambiguity in local names and similar apparent appearance, market samples of Punarnava are often adulterated with various species of Trianthema and Sesuvium. These adulterated samples contain neither the Punarnavine alkaloid, nor does it possess anisocytic stomata but possess paracytic stomata. Comparative study of stem anatomy showed two main characteristic differences. First, plenty of starch grains can be seen in both the ground parenchymatous tissues present in between successive cambia and xylem parenchyma of Punarnava which is not observed in species of Trianthema, and second, the phloem around the xylem of Punarnava root has semi-circular or eccentric patches, while that of Trianthema only has narrow strips. This study is focused on comparative SEM study of leaf morphologies and anatomy of leaf, stem, and root of Boerhaavia diffusa L., Trianthema portulacastrum L. and Sesuvium portulacastrum L.