I got some mercs killed coming up with this guess, but the group members lived, so we're fine. Underfoot Mushroom?
Lol, glad you lived! Yes! Impossibly blue in the ground, magically orange-yellow and white when you pick it. It can't be real, or at least can't be safe to consume, but it can be brewed. One recipe to give to the guards in Katta Castellum for faction, or the more common use: Kaladim Constitutional.
That was a good one. I kept skipping past Underfoot Mushroom thinking it was from the Underfoot expansion.