Highly branched stem is greenish purple, swollen at nodes, prostrate, or ascending to a height of up to 1m. Leaves silvery on the undersurface are simple, thick and glabrous. Flower is small pink or white on long axillary peduncled umbellate clusters. Root is stout fusiform with a woody rootstock and has a bitter nauseous taste. Roots of Trianthema species are sometimes mistaken for punarnava roots.

Constituents

Major constituent is punarnavoside—a phenolic glycoside, 0.03–0.05%. Others include rotenoids — boeravinones A, B, C, D, and E, Lignans—liridodendron, syringaresinol, some flavones and sterols. Roots contain a purine nucleoside, hypoxanthine-9-arabinofuranoside and boeravine, ursolic acid and β-sitosterol. It contains an insect-moulting hormone, β-ecdysone. In addition, it contains potassium nitrate and other potassium salts.

Traditional uses

Used in Indian traditional medicine since times immemorial, ayurvedic practitioners recognize two varieties of the plant—one with white flowers called “swetha punarnava” and the other with red flowers “raktha punarnava.” Ayurvedic formulary “svetapunarnava” as another species is the B. verticillata.

The drug is a bitter, astringent, cooling, anthelmintic, diuretic, diaphoretic, emetic, and laxative and tonic.

Whole herb in the form of a juice is given internally as a blood purifier. Dhanvantri has described the white variety in his nighantu as possessing laxative and diaphoretic properties. The red variety is bitter and is considered effective in the treatment of oedema and biliousness. Charaka used it in the form of an ointment in leprosy and skin diseases and as decoction for kidney stone removal. Local applications of the root paste have been recommended in oedematous swellings. The drug being an efficient diuretic relieves oedema and is used in urinary tract diseases. A rasayana or rejuvenating drug, Punarnava is an ingredient of the famous Chyawanaprasha. It is also eaten as a vegetable in curries and soups.