Acorus calamus (L.), or sweet flag, is the number one herb both for medicine and ritual among Eastern Native American tribes (survey of tribal elders a few years ago).  During Sun Dance ceremony when First People may sing for ten hours or more they put a piece of Calamus root between cheek and gum to keep their throats moist.  The root is a sialagogue, it makes your mouth glands secrete juices. (see more also caution)

Below:  Sweetflag roots and rhizome.