Comparative Study on the Morphological and Anatomical Characteristics of Trichosanthes kirilowii var. kirilowii and T. kirilowii var. japonica (Cucurbitaceae)

Background: The genus Trichosanthes (Cucurbitaceae) comprises biennial and perennial herbs distributed across East Asia and Australia. The roots of T. kirilowii var. kirilowii have traditionally been used in the herbal medicine Trichosanthis Radix. The two varieties, var. kirilowii and var. japonica, are distributed in Korea; however, their morphological similarities make them difficult to distinguish, and the taxonomic status of var. japonica remain understudied. Therefore, we investigated the micromorphological and anatomical characteristics of the T. kirilowii complex in Korea. Methods and Results: External morphological and micromorphological traits of leaves and roots were examined using stereomicroscopy, light microscopy, and scanning electron microscope (SEM), while anatomical characteristics were analyzed using a digital slide scanner. The results clearly distinguished the two varieties based on their external morphological and anatomical traits. Conclusions: Lenticels on roots, leaf epidermal cell size, mesophyll cell density, and starch granule density in the root parenchyma were useful diagnostic characteristics. These findings provide morphological and anatomical evidence supporting the recognition of T. kirilowii var. japonica as an independent species, T. japonica. Further studies incorporating diverse populations and multidisciplinary approaches are required to validate these diagnostic traits and assess their potential as a source of herbal medicines.