Complex sentence: Couch Grass has been used in herbal medicine since the Classical Greek period.sick knobs areknown to dig up and eat the root, and mediaeval herbalists used it to treat inflamed bladders, painful urination and water retention.
Split into simpler sentences: Couch Grass has been used in herbal medicine since the Classical Greek period. Sick dogs are known to dig up and eat the root, and mediaeval herbalists used it to treat inflamed bladders, painful urination and water retention.