Horse Gram

Horse gram is a slender, twining or semi-erect annual legume with trifoliate leaves, small yellowish flowers and narrow, curved pods holding five to ten seeds. The seeds are small, flattened and kidney-shaped, about four to six millimetres long, ranging from pale brown to reddish brown, black or mottled in different landraces. Cooked seeds have an earthy, slightly bitter, robust flavour, and they need long cooking because the seed coat is hard. Horse gram is sold whole and dried, split as dal, ground into flour, and sprouted. In southern India it is commonly soaked, boiled and simmered into a thick, dark soup or rasam.

Horse gram is believed to have been domesticated in the Indian subcontinent, and archaeological finds in southern India point to cultivation several thousand years ago. It may also have been grown early in parts of Africa and Southeast Asia, though India is considered the primary centre. The genus name Macrotyloma combines Greek words suggesting large lumps or swellings, and uniflorum refers to flowers borne singly or in few-flowered clusters. The English name reflects its long role as fodder for horses and cattle, while regional names such as kulthi, from Sanskrit kulattha, and kollu in Tamil reflect its use as human food across languages of South Asia.

Horse gram is one of the oldest pulses in South Asian farming, appearing in early Sanskrit and Tamil sources. Ayurvedic and Siddha texts mention kulattha as a food and medicinal pulse, traditionally recommended during damp or cold seasons and used in teas and soups. Because it grows with little rain and no fertiliser, it became a crop of marginal land and poorer households, which gave it a reputation as a lowly food even though its nutrition is considerable. It was fed to draught animals, especially horses, in much of the region, and British colonial writers noted this animal use. In recent decades, interest from nutrition researchers and sustainable agriculture advocates has revived the crop. Genebanks in India, including those supported by international crop trusts, hold diverse collections, and growers in Karnataka, Andhra Pradesh, Tamil Nadu, Uttarakhand and Nepal still cultivate regional varieties. Sprouted horse gram has also become popular in urban health food circles.

Horse gram is cooked as a dal or thick soup, such as kollu rasam in Tamil Nadu and ulava charu in Andhra Pradesh, and is stewed with spices and coconut in Kerala and Karnataka. Roasted seeds are ground into chutney powders, while sprouts go into salads and stir-fries. In the Himalayan state of Uttarakhand, gahat dal and its stuffed flatbreads are local specialties. Traditional medicine uses the cooked liquor in warming remedies for colds and the seeds in poultices. The plant is also grown as fodder, cover crop and green manure.

Horse gram is a good plant source of protein, fibre, iron and calcium, and it contains polyphenols and other phytochemicals that are being studied for antioxidant and blood sugar effects. Laboratory and small clinical studies suggest possible benefits, but evidence is preliminary and cannot support claims of treating diabetes, kidney stones or obesity, which are sometimes made in traditional contexts. Like most pulses it contains antinutritional factors such as trypsin inhibitors and tannins that are reduced by soaking, sprouting and thorough cooking.