Sterculia urens (Kullu) Roxb.: An Important Non-Timber Forest Species of India and Its Multifaceted Uses

Abstract

Sterculia urens Roxb., commonly known as Indian tragacanth or Karaya gum, is a tree species native to India and widely distributed across its agroecological regions. It is a declining non-timber forest species valued for its gum exudates, which have significant commercial importance in international markets. Consequently, the species requires conservation to ensure its sustainable availability in nature. In addition to its economic value, S. urens is recognised for its medicinal properties and is widely used in traditional Indian healthcare systems, including Ayurveda and Unani. The species is categorised as Vulnerable by the International Union for Conservation of Nature (IUCN) among threatened medicinal plants of central India, emphasising the need for effective conservation and management. In India, Sterculia urens is distributed across several states, including Andhra Pradesh, Maharashtra, Gujarat, Odisha, Rajasthan, Karnataka, Bihar, and Chhattisgarh. Within Chhattisgarh, commercially significant populations occur predominantly in the forested regions of Dantewada, with smaller populations reported from Kanker, Jagdalpur, Bijapur, Sukma, Korea, and Gariyaband districts. Commonly known as gum karaya, S. urens is an economically important tree species belonging to the family Sterculiaceae, typically inhabiting dry and rocky forest ecosystems. Besides its industrial and commercial value, its roasted and cooked seeds serve as a supplementary food source for economically disadvantaged communities.  The seeds of Sterculia urens comprise approximately 56% kernel, containing about 35% protein, 26% oil, and 28% carbohydrates. The seed oil has potential applications in both the edible oil and soap manufacturing industries. The species produces gum karaya, a complex polysaccharide with extensive industrial applications, particularly in the pharmaceutical, leather, bakery, and dairy sectors. In addition to its commercial significance, gum karaya and related gum-resins possess notable medicinal properties and have been traditionally utilised in Ayurvedic and Unani systems of medicine for the management of various ailments, including fever, cough, common cold, dysentery, and sexual disorders.