4 Team of scouts was deployed, it consisted of 1 healing priest, two battle-type priests, and a divination priest. This combination was perfect to hunt someone down. In this case, it was a root of some kind.
It was information gained by the church after they deployed the saintess. Although she had never seen the roots in person, she could get a glimpse through her godly divination. Her ability is only second to the church.
Usually, if you want a precise divination, you would need to prepare to lose something big. However, saintess have the privilege of being god's chosen. Only require her faith and the item that corresponds to the thing you want an answer to.
When they arrived in Guragua to quell the mutant animals, they had already encountered the root. Well, more accurately, her subordinates had encountered it. They battled the root, managed to collect some parts, and brought them back to her for divination.