Moss

Moss is a spell reagent. It can also be used as food and ingredient.

Source
Moss can be obtained by:
 * Purchased for from vendors
 * Harvested in wilderness outside of cities
 * Dropped as loot by caster mobs
 * Loot from chests, treasure maps, and Fishing maps

Vendors

 * Valus
 * Eldeir Village
 * Pyros Landing
 * Oasis
 * Black Forest Outpost
 * Belhaven

Spells
Moss is a reagent for the following spells:
 * Portal
 * Resurrection
 * Ruin
 * Lightning
 * Energy Bolt

Used In
Moss is used as an ingredient to make spell scrolls through Inscription for the same spells listed above. It is also used in Alchemy to make:
 * Mending Potion