Indian quassia; quassia wood; picrasma wood
Refers to the tree Picrasma quassioides or its bitter wood, used in herbal medicine and as a bittering agent.
Quassia wood is sometimes used as an ingredient in traditional Chinese medicine.
This tea contains quassia extract.
The name ニガキ (苦木) literally means 'bitter tree', from the extremely bitter taste of its wood and bark.