Where names are coined — the striking of a new word into circulation; and the cool green herb wearing the same freshness.
Latin moneta (coinage, from the temple of Juno Moneta where Rome struck its coins) gives the striking sense; the herb is a separate word, Latin mentha, from Greek minthe — two unrelated roots sharing one English spelling.
The striking of something new into circulation — a word made currency, sharing its name by accident with a herb that only wears the same freshness.