Mana Flower

The Mana Flower is an Accessory that acts as an enhanced Nature's Gift, in that it reduces mana usage by 8% (stacks).

It also enables auto-consumption of any mana-restoring items, making it so that instead of clicking on their potions in the hotbar, mages can focus on the fight at hand. This mechanic of the Mana Flower confirms that the lack of Potion Sickness from mana potions is purposeful, and not a glitch or anomaly.

This accessory is extremely useful in any boss fight or PvP scenario, and should be acquired as early on as possible by players oriented towards magical gear.

Tips On Obtaining
Two Lesser Mana Potions can easily be found within the Dungeon, and Nature's Gift is relatively common in the Underground Jungle. Use a Glowing Mushroom to make a Mana Potion with the the Lesser Mana Potions, and craft it with the Nature's Gift at a Tinkerer's Workshop.

Trivia

 * Though the Mana Flower takes merely a Mana potion, the sprite for it shows it as being a Greater Mana potion.