noun
rock tripe
An edible lichen used in traditional medicine in Korea, China, and Japan. Typically referred to by its katakana name.
イワタケは岩の表面に張り付くように生える地衣類です。
Rock tripe is a lichen that grows clinging to rock surfaces.
韓国ではイワタケを乾燥させて漢方薬として使うことがある。
In Korea, dried rock tripe is sometimes used as an herbal medicine.
The name literally means 'rock mushroom' (岩/石 + 茸). The exact origin is uncertain, but it describes the lichen's appearance and habitat.