'bara' originates from Japanese, specifically written with the characters '薔薇' which were chosen to represent the native word; the characters themselves refer to fragrant plants.

'bara' was an indigenous Japanese word for a wild or fragrant rose and over time the spelling and writing were standardized using the kanji compound '薔薇' in modern Japanese.

Initially, it referred more narrowly to wild or fragrant roses; over time it came to be used for roses generally, including cultivated varieties (and later as a slang/genre term in modern contexts).