'heterosepalous' originates from Greek and New Latin, specifically the prefix 'hetero-' from Greek 'heteros', where 'heteros' meant 'other' or 'different', and 'sepalous' from New Latin 'sepalum', where 'sepalum' meant 'a sepal (a leaflike part of a flower)'.

'heterosepalous' developed by combining the Greek-derived prefix 'hetero-' with the botanical New Latin element 'sepalum' (coined in the 19th century) to form the English adjective 'heterosepalous'.

Initially coined to describe 'having different sepals' in botanical Latin/English, the term has retained that specialized botanical meaning in modern usage.