Histo-anatomy and morphology of aquatic plants Bacopa amplexicaulis (Pursh) Wettst., Bacopa lanigera (Cham. & Schltdl.) Wettst., and Bacopa rotundifolia (Michx.) Wettst.

Abstract

Plants of the genus Bacopa are ornamental water plants used in aquascape design. This study examined the differences in morphological and anatomical characteristics in the roots, stems, and leaves of three Bacopa species, namely B. amplexicaulis, B. lanigera, and B. rotundifolia. The identification of morphological structure was based on a book entitled Morfologi Tumbuhan (Plant Morphology) by Tjitrosoepomo (2016). Anatomical identification referred to the book on Plant Anatomy by Crang et al. (2018). The data collected were analyzed descriptively and quantitatively. Bacopa rotundifolia had the smallest leaf size, while B. amplexicaulis had the largest leaf size. All of the observed species had leaf anatomical characters in the form of anomocytic stomata. Bacopa amplexicaulis had the largest stem diameter, measuring 4.38 cm. Trichome and aerenchyma structures were found in all stems of the test species. Bacopa lanigera stems had the most trichomes, 72 in one cross-section. Meanwhile, B. amplexicaulis had the longest trichome (1.590 µm). The aerenchyma of B. amplexicaulis and B. lanigera was flat, while that of B. rotundifolia was oval. Bacopa amplexicaulis had the longest aerenchyma at 957 µm. Only B. lanigera had a trichome on the root.