East Indian screw tree

H. isora is a small tree or large shrub, five to eight metres in height. It has grey bark and alternately arranged, hairy, ovate leaves with serrate margins. Its flowers are brick red or orange-red, and its fruits are green when raw, brown or grey when dried, and twisted, with a screw at its pointed end. Seeds of the plant are black or brown and are highly polished, roughly rhomboid, and rectangular or triangular. Pollinators of the flower include the jungle babbler, the golden-fronted leafbird, the ashy drongo, and the white-bellied drongo.

H. isora is a tropical Asian plant. It is found throughout India and Pakistan, Nepal, Myanmar, Thailand, and Sri Lanka. However, it gregariously grows in dry deciduous forests of central and western India on hill slopes. It is also found on the Malay Peninsula, Java, and Australia.

H. isora is a rich source of antioxidants, carbohydrates, proteins, fibre, calcium, phosphorus, and iron. Active phytoconstituents include gallic acid, caffeic acid, vanillin, and p-coumaric acid. Cucurbitacin b and isocucurbitacin b have been isolated from the roots. Additionally, Satake et al. (1999) isolated rosmarinic acid and their derivatives; isoscutellarein and their derivatives; D-glucopyranosyl isorinic acid with rosmarinic acid; helisterculins A and B; and helisorin.