Elm

The elm is a large deciduous tree native to planet Earth.

A large elm tree with a circular bench was located on the Starfleet Academy grounds in San Francisco. It was located close to the parade grounds. Jean-Luc Picard and Simon Tarses used to sit under that tree during their Academy days and watch and study. 

It was possibly the bark of this prized elm tree, cherished by Boothby, that Cadet Picard carved the initials A.F. into. 

When Captain Kathryn Janeway asked a holographic Leonardo da Vinci what he imagined his life would be like if he were a sparrow, he replied that he'd make his home in a tree, in the branch of an elm and would hunt insects for food, straw for his nest and in the springtime he would sing for a companion.