Vines

Vines are a species of plant in Metroid Prime. They make only one appearance in the game, in the Sunchamber. During the battle against Flaahgra, the vines grow over and cover the door from Sunchamber Access, preventing Samus from returning through that door. Even after Flaahgra's death, the vines remain on the door, and are indestructible. They can only be removed on a return visit after Samus gains the Artifact of Wild from defeating three Chozo Ghosts in the room. When this happens, the vines will disappear.

Scan
"Scan indicates this network of vines is invulnerable to weapons fire."