Pop Green

Pop Greens (ポップ グリーン, Poppu Gurīn) are the seeds of hostile plants that possess insantaneous growth. They exist in the Grand Line, on the island called "Greenstone" they are present in abundant numbers on this island. These seeds have various uses.

History
Heracles uses this seeds as bullet and weapon it has also various uses. Heracles teaches Usopp how does it works after Usopp decides to become stronger.