Locate Release For Free

Poison ivy, poison oak, and poison sumac grow in wooded or marshy areas throughout North America.

The roots are too deep from the surface, so you'll need to find another way. Luckily, there just happens to be one in a subway tunnel under construction beneath Port Adams. Head over to the port to find that the Arkham Knight already has a drone force waiting for you.

Use the sonar and follow the radar to where the roots get larger and are clustered together. When you spot a red dot on the sonar (it will be in an alley where you can spot a small cluster of roots coming out of the ground), head to where it is and then charge up a sonar blast to get the plant to surface.

Use the sonar and follow the radar to where the roots get larger and are clustered together. When you spot a red dot on the sonar (it will be in an alley where you can spot a small cluster of roots coming out of the ground), head to where it is and then charge up a sonar blast to get the plant to surface.

Activate Batmobile's battle mode in the last part of the tunnel and start using the sonar to scan your surroundings. Just as before, observe the mini-map that will lead you to the plant you seek. Stop in the place shown on the picture above and hold the sonar key/button in order to shoot a bullet underground.

Drive out of the underground parking lot, activate the Batmobile's Battle Mode and start pressing the Sonar key/button. Each time you use the Sonar look closely at the mini-map, as it will display roots leading to the Ivy's Plant.

How to track down Poison Ivy's plant, access the subway network at Port Adams, and then protect the plant from the local militia forces. Use the arrows on the road to find your way over to the island, then immediately enter Battle Mode and deploy the Sonar.