One might expect the best part of a mountain hike to be the views, but sometimes it turns out to be the stories told by a knowledgeable guide. And in Sikkim, almost every shrub, grass and tree seems to have something revealing about it: local mugwort is used as a poultice for cuts, the yellow ball-shaped flowers of the majito make a dark blue dye, and lycopodium japonicum can be used against TB – and, oddly, its mossy-looking filaments release a dust once used as a lubricant in colonial rifle barrels.