India, April 17 -- As the bright, high-altitude morning sun hits their silver, the bejewelled women of Johar break into a slow, rhythmic dance. Men, bedecked in turbans and swords, match their steps, all filed in a neat queue that snakes forward through lush forests and across undulating hills. I move with them, fixated, still in disbelief at my presence there.

The synchronised, swashbuckling entourage moves gently uphill and culminates around a prickly bush in bloom. As the music rises to a crescendo, in a single masterstroke, the bush is hacked and uprooted. Multiple swords rain down on it, and amid beats and chants, the kangdali is destroyed.

Legend has it that this nettle family bush once sheltered the army of the 19th-century comma...