This room is close in proximity to a Save Station, and the exit is directly connected to the room with the first Super Missile Tank (without Sequence Breaking to get them early). It is a tall and thin shaft with two halves. The second half is inaccessible until the Spore Spawn is killed.
The first half is square and features a floor of dense vegetation, with a network of vines running up the walls and across the ceiling. Each side of this part of the room has a ledge. The corner of these ledges connected to the walls is a useful place to crouch and avoid damage. In the background is a wall of bluish vegetation with blue "blossoms". The Spore Spawn hangs from this wall. Lining the underside of the ceiling are four flower buds that create spores, which are useful during the coming battle as they drop Energy Capsules and Missile Ammo when shot.
When Samus first enters the room through the bottom door, it shuts under her and turns into a Green Hatch. The Spore Spawn awakens and then begins to fight Samus. Once the boss is killed, the entire room turns brown (including the Spore Spawn itself) and part of the ceiling explodes to reveal the second, smaller shaft, consisting of five ledges made of the same material as the floor below. These lead up to a metal ledge on the upper right, underneath the door to the next room.
- Spore Spawn
- 4 flower buds
- Unlike all other boss rooms in Super Metroid, the door to enter this room turns into a Green Hatch instead of a Grey Door. If Samus acquires the Super Missiles early through Sequence Breaking or through the Spacetime Beam reset, she can shoot the door at the bottom and escape the battle. If Samus returns to the room, Spore Spawn will have recovered any damage she dealt to it before escaping.
- After Spore Spawn's defeat, the Silence theme will play in this room on future visits.
- If Samus Wall Jumps off the Spore Spawn's dead husk, it will shake. It is one of a few objects in the game with this distinction.
- The vegetation of Nettori's room in Metroid Fusion also seems to shrivel up and die, turning a decaying color after that boss is killed.