It has a thin grey bark and shiny elliptical leaves. The flowers are arranged in terminal cymes,and are greenish white. Alkaloids are present in all the parts of the plant. Strychnine and brucine have been known for their action on the neuromuscular junction which is paralysed by a curare like action of depolarization with initial tetanic spasm leading to paralysis. At the spinal level, the action of strychnine is to produce generalized muscle spasm-opisthotonic tetany is a characteristic of strychnine poisoning.
Death results from paralysis of the respiratory muscles.
Small doses of the alkaloids stimulate the respiratory centre, larger doses paralyse it.juice of the fresh bark is used in cholera and dysentery. The dried bark is given either as a decoction or as a paste. A poultice made of leaves is used for chronic ulcers. The seeds are used by ayurvedic physicians after a pre- treatment known as shodhana to detoxify the drug. This is done by soaking the seeds in cow's urine and peeling off their softened outer coats after 7 days.