Adaptive features of the vegetative organs of some common riparian plants in the lower Con river, Phuoc Hoa commune, Tuy Phuoc district, Binh Dinh province
Abstract
The riparian vegetation along the lower Con River plays a crucial role in regulating the microclimate, stabilizing soil, providing protection during the rainy and stormy season, and contributing to the aquatic ecosystem. This study was carried out on four herbaceous and undershrub species in Magnoliophyta. Morphological comparison, microsurgery, double-staining, microscopic measurements and imaging of roots, stems, and leaves were applied to identify adaptive features in the vegetative organs of the studied species. The results revealed that the plant species in the study area are adapted to high light conditions, as evidenced by the abundance of trichomes on the leaf epidermis and the well-developed palisade mesophyll (accounting for up to 56.22% of leaf thickness). Aerenchyma tissues were strongly developed, forming large air cavities in both roots and stems (up to 63.49% of root radius). These species also exhibited a low number of xylem vessels with large vessel diameters (25.00 ± 4.00 vessels/mm² and 109.92 ± 13.15 µm in secondary roots; 5.33 ± 0.33 vessels/mm² and 114.83 ± 20.08 µm in primary stems), facilitating adaptation to hypoxic and waterlogged conditions during the rainy season. The presence of sclerenchyma surrounding vascular bundles in roots and stems, scattered distribution of calcium oxalate crystals and sclereids in the leaf mesophyll support the species’ tolerance to mechanical stress, such as wind and storms.