(Jacq.) Willd.Synonym: T. divaricata (L.) R. Br. Ervatamia coronaria (Jacq.) Staph. E. divaricata (L.) Burkill.Family: Apocynaceae.
Habitat: Sub-Himalayan tract. Cultivated in gardens.
English: East Indian Rosebay.Ayurvedic: Tagar, Nandivriksha (The Wealth of India); Nandi Pushpa. (Tagar is equated with Valeriana hardwickii and Nandivrksha with Cedrela toona.)Siddha/Tamil: Nandiyavattam.Folk: Tengari, Chaandani.Action: Leaves—milky juice, antiinflammatory; applied to wounds. Flowers—mixed with oil, used in skin diseases. Root—acrid, anodyne; relieves toothache, also used as a vermicide.
Various parts of the plant are used in the indigenous system of medicine for the treatment of skin diseases and cancer. A decoction of leaves is used as antihypertensive and diuretic.The plant from Sri Lanka (root, leaves and flowers) contain several indole alkaloids including voacristine, voacangine, coronaridine, vobasine, tabernaemontanine and dregamine. Isovoacristic hydrochloride, found in the plant, caused bradycardia in frogs and rabbits. The flowers contain an alkaloid tabersonine which is reported to show hypotensive effect on anaesthetized cats.Coronaridine showed autonomic as well as CNS activity when tested for biological action in animals. It produced analgesia and was effective in suppressing foot-shock-induced rage in mice.Indole alkaloid (I) inhibited HC1- induced ulcer in mice by 48.8%.The crude alkaloid extracts of the leaves, bark and flowers exhibit antibacterial activity against Staphylococcus aureus.