This is a Rare collection of Liquids.
All of the items in this collection can be found in the water near Sperry's Spore Farm in the Nettleseed area of Briarwood. They are found predominantly around the 3 waterfalls.
Find Sparkling Water <Rare Collection> and collect it to find an item from the list, below.
The item, Magical Nettleseed Mixture, is a reward for completing the Nettleseed Liquid Concoction collection.