This paper offers a detailed examination of the morphological, micromorphological, and phytochemical profiles of two Tribulus species found in Vietnam: Tribulus cistoides L. and Tribulus terrestris L. The research seeks to outline and contrast the morphological and anatomical traits, together with the phytochemical content in the stems and leaves of these species, to explore their possible uses in pharmaceuticals. This was achieved through the double-staining technique and initial phytochemical screening via specific color reactions. Findings indicate that T. cistoides and T. terrestris share similarities in habitat, oblong-lanceolate leaflets, and ovate-lanceolate stipules, yet differ noticeably in flower and fruit morphology. Regarding micromorphology, both species exhibit comparable structures in the leaf midrib (single upper and lower epidermal layers, palisade mesophyll, vascular bundles, sclerenchyma, and parenchyma), leaflet blade (dorsiventral with single upper and lower epidermis, palisade and spongy mesophyll, plus vascular bundles featuring Kranz-type sheaths), and stem (single epidermal layer, parenchymatous cortex, pericyclic bundles, vascular bundles, and pith). Differentiation is possible through the number of xylem rows in leaflet vascular bundles, the spongy mesophyll layers in leaf blades, and characteristics of stem vascular bundles. Preliminary qualitative analysis revealed the presence of key compounds, including alkaloids, saponins, and flavonoids, in both species, while polyphenols, tannins, coumarins, quinones, terpenoids, amino acids, and carbohydrates were detected for the first time in T. cistoides. These results facilitate precise identification and standardization of medicinal resources, aid in conservation assessments, and lay the groundwork for subsequent pharmacological and biological investigations.
