Waltheria indica (L.) is a species in the list of medicinal plants in Vietnam. However, information about this species is still at the basic level. In order to provide more data on this medicinal plant, the present research has gone into further on the characteristics of the plant through morphological classification method, observing the thin slices of vegetative and reproductive organs and measuring with a reticule on the eyepiece and a stage micro-meter equipped for a light microscope. Combination of statistical analysis of botanical morpho-anatomical traits with characteristics of soil and climatic where the plants distribute was conducted to find ecological adaptation of the plants. The results showed that the plants growing in regions with different ecological conditions had significant differences in structural characteristics. This is the basis for collecting the medicinal plants Waltheria indica (L.) and continue to determine their pharmacological properties in the future.

This study aimed to investigate the antibacterial ability of Waltheria indica species collected from two communes of Phan Thiet city, Binh Thuan province. Research methods included making ethanol extracts and decoction and investigating their ability to inhibit bacteria through agar well diffusion method and determining the minimum inhibitory concentration (MIC). The results showed that the ethanol extract was resistant to 5 tested strains of bacteria (Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Escherichia coli) with diameters of bacterial inhibition zones ranging from 6.76 to 14.50 mm, in which the resistance to Gram-positive strains was better than Gram-negative strains. The decoction inhibited only 3/5 of the tested bacterial strains (S. aureus, E. faecium, E. coli) with MICs from 125 to 750 mg/mL (dry weight of plant per volume of decoction). The antibacterial activities of extracts from the stems, leaves, and roots of the plants were different. Samples obtained from the 2 sites also showed different antibacterial capacities.