Aims: This work is a survey of the distribution of vascular plant species that have medicinal values. Methodology: The census, medicinal uses, economic benefits and existence threats of the plants were reassessed. Results: Additional members of Asteraceae have been discovered from 12,000 to 20,000 species with Centaurea species (500) mostly used in the family. Stevia produces steviol glycoside that is 200-300 sweeter than sugar with market value of 2-3 billion yen/year. Species of Orchidaceae (20,000) have been discovered with 3,000 and 2,500 endemic to Columbia and Ecuador respectively. Other members of family that have been increasingly discovered are Fabaceae (8,000), Euphorbiaceae (7,300) with Euphorbia species (1,600), Rosaceae (3,000), Boraginaceae (2,000), Polygonaceae (1,200) whereas Acacia (1,380) and Salvia (900) species have also been discovered.
Conclusion:The increased number of species may be due to additional discovery, genetic polymorphism and evolution. However, threats to their existence may be due to urbanization, deforestation, over exploitation, environmental pollution and fires. Therefore, management
Review Articlestrategies aimed at conserving medicinal plants biodiversity are very important for development of raw materials for pharmaceutical industries and synthesis of drugs for treatment of human and animal diseases that can contribute to world economy. Despite more plants with medicinal values have been discovered their over use could threaten their existence. Hence, North America, Argentina, China and Australia have started embarking on genetic propagation of their threatened plants.