Sunflower

Sunflowers are large plants. They are not grown from seeds like most other plants, but are instead placed fully-grown, either naturally on world generation or by the player. They can be freed with a pickaxe, and are also sold by the Dryad.

Sunflowers provide the following functions:
 * Before Hardmode, they prevent the spread of Corruption and Crimson (they cannot stop either, nor Hallow, once Hardmode begins).
 * They provide the Happy! buff to players within a 50-tile radius, which grants a +18% movement speed bonus and a reduced enemy spawn rate.
 * Each Sunflower decreases an area's total corruption rating by 5 tiles. This rating is used to determine whether NPCs will reject Housing. If placed in large quantities, they can allow NPCs to live near tainted blocks. This effect covers a radius of about 25 tiles.

Sunflowers can only be placed on Grass and Hallowed Grass (at any height) but require an absence of walls behind them when placed (walls can be placed behind them afterward, however). They cannot be placed on Corrupt Grass, Crimson Grass, bare Dirt Blocks, nor in Clay Pots. They have a very low chance of spawning more sunflowers in a small area.

History
Tournesol