'mottled-leafed' originates from Modern English as a compound of 'mottled' and 'leafed'. 'Mottled' derives from 'mottle', ultimately from Middle English 'mot' meaning 'spot', and 'leafed' is formed from Old English 'lēaf' (leaf) plus the adjectival suffix '-ed' meaning 'having'.

'mottle' developed from Middle English forms such as 'mot'/'mote' (meaning 'spot') into the verb/adjective 'mottle'/'mottled', while 'leaf' comes from Old English 'lēaf'; these elements combined in Modern English to form the descriptive compound 'mottled-leafed'.

Initially the components referred separately to 'spot' (mottle) and 'leaf'; over time the compound came to mean specifically 'having spotted or variegated leaves' and has retained that descriptive meaning.