Horse gram (Macrotyloma uniflorum), known across India as kulthi, kollu, hurali or ulavalu, is a small, hard, drought-hardy pulse of the dry tropics and one of the most protein-dense of all cultivated legumes. Its tiny flat seeds — reddish-brown, grey, black or mottled — are simmered into the tart South Indian broth rasam, roasted and ground into spice podis, boiled with the cooking water drunk as a savoury soup, or sprouted.