The Ohio Buckeye is the official state tree of Ohio.
The green tree frog was adopted as official state amphibian of Louisiana on June 22, 1993.
The White Oak is the Official State Tree of Maryland.
The tulip tree is the official state tree of Indiana.
The Kukui nut tree (Candlenut tree) is the state tree. I do not think there is an official state nut- but the macadamia is pretty popular!
The Pine is the official state tree of Arkansas.
The American Elm is the official state tree of Massachusetts.
There is no state with the water oak as an official state tree.
The willow ptarmigan is the official state tree in Alaska. Sitka spruce is the official state tree in Alaska. Alaska's state flower is the alpine forget-me-not.
The Buckeye Tree, is the state tree of Ohio, Ohio State University, being the official state University of Ohio, used the name of the State tree (Buckeye Tree) for their official athletic nickname.
The state of Maine is often referred to as the Pine Tree State, though there is no state with the phrase Tree State as an official nickname.
The Whit Oak is the Official Tree of Maryland.