'alismaceous' originates from the Latin word 'Alisma', referring to a genus of aquatic plants, combined with the suffix '-aceous', indicating belonging to a family or group.

The term 'alismaceous' was derived from the Latin 'Alisma', which was used to describe water plantains, and evolved into the modern English adjective describing the plant family.

Initially, it referred specifically to the genus 'Alisma', but over time it evolved to describe the entire plant family Alismataceae.