What made you want to look up nettle tree? Please tell us where you read or heard it (including the quote, if possible).
The Federalist is an online magazine that covers politics, policy, culture, and religion. It was co-founded by Ben Domenech and Sean Davis; senior editors include David Harsanyi and Mollie Hemingway.
According to the Wex Legal Dictionary, federalism is a governmental system in which two levels of administration control the same piece of land. Federalism is prominent in the governing structures of many current countries, including the United States, India, Belgium and Brazil.