State Tree – adopted in 1931. The Tulip tree is the state tree of Indiana. Also known as the Yellow Poplar, it reaches great height and is found throughout the state. In May or June it sports bell-shaped greenish-yellow flowers. Its soft white wood has many uses. In pioneer times it was the Monarch of the great forests that covered Indiana. It is indigenous to the state. Now comparatively rare, it is used mostly in ornamental planting.