Elm
The elm was 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. Both Jean-Luc Picard and Simon Tarses recalled sitting under that tree during their Academy days. It was Picard's favorite place to study, while Tarses enjoyed watching the training drills, imagining himself as an officer. ()

Cadet Picard once carved the initials A.F. into Boothby's prized elm tree. ()

When Captain Kathryn Janeway asked a holographic  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. ()

External link 
 

de: Ulme
Earth plants