A medicinal herb from a faraway world. While exceptionally effective for treating dragons, it should never be ingested by humans as it is highly toxic. It seems that there is no other known method to cure a dragon of injuries or illness besides this herb, making it a very precious item in that world.Final Fantasy Brave Exvius description
Dragon Grass is a plant that is a panacea for wind drakes, but deadly poison to humans.
In Bartz's world, dragon grass grows at the summit of North Mountain. Lenna's wind drake, Hiryu, flies there after being wounded and separated from King Tycoon, but the dragon grass is surrounded by poisonous flowers. Lenna crosses the field to retrieve it, and the plant heals Hiryu (who then heals Lenna of the poison).
The plant also grows in Galuf's world in Drakenvale, the ancestral home of the wind drakes. It has mutated into a dangerous monster called Dragon Flower and attacks anything that approaches it. Galuf speculates that the transformation is responsible for the near-extinction of wind drakes there. The dragon grass returns to normal after the monster is defeated, and the party takes it to Castle Bal to treat Krile's wind drake of its wounds.
The wind drake initially refuses because of the monstrous mutation, so Lenna takes a bite to convince him it is safe, in spite of the it being deadly to humans. It works and the wind drake is healed, and Krile heals Lenna with an item.
Dragon Grass is the currency for the Final Fantasy V event, Castle Exdeath.