Ask what incense smells like in a Hindu temple and the answer for most of India is guggul, not frankincense. The gum resin of Commiphora wightii, a thorny shrub of the dry western states, is the base of dhoop, the thick compounded incense pressed into cones and sticks or burned loose on charcoal, and it does the job that frankincense does around the Mediterranean.
The plant is a close relative of the myrrh tree, and the resins behave alike: tapped from a cut in the bark, hardening into brittle lumps, burning with a bitter and slightly medicinal smoke. Guggul is sharper and less sweet than frankincense and reads as more astringent.
It is also a major Ayurvedic drug rather than only an aromatic. The classical texts prescribe it for stiff joints, for obesity and for the condition they call ama, and modern pharmacological interest in guggulsterones for cholesterol came directly out of that indication. The Sushruta Samhita treats it at length.
The plant is in trouble. Demand for the resin has outrun the shrub's ability to recover from tapping, wild Commiphora wightii is assessed as critically endangered, and a substantial part of what is sold as guggul is now adulterated or is a different Commiphora species altogether. Cultivation exists but the shrub is slow and yields poorly.