Boughs of, were to be carried in festive procession on the first day of the feast of Tabernacles (Lev. 23:40). This was probably the olive tree (Neh. 8:15), although no special tree is mentioned.
Easton’s Bible Dictionary
Goodly Trees
Easton’s Bible Dictionary, M. G. Easton (1897). Public domain, from the CrossWire SWORD module.