Amaranth is the only flower that grows in the Netherworld. It has several medicinal uses for both humans and Rephaim. The essence of amaranth is used to heal spiritual wounds, such as poltergeist scars or a damaged dreamscape. The amaranth was also the basis for the name of the Ranthen.
- Nashira Sargas gives Warden doses of amaranth as an incentive to remain at her side as it eases the pain from the scars he received as a punishment for Bone Season XVIII.
- Warden gives Liss Rymore amaranth to help revive her after her cards--her connection to the æther--were burned.
- Warden also leaves a small vial of amaranth in Paige Mahoney 's backpack after she escapes. She later uses it to remove the incriminating mark of the London Monster.