A Christian moveable feast that falls on the Sunday before Easter is called Palm Sunday. The feast commemorates Jesus' triumphal entry into Jerusalem. That is event mentioned in each of the four canonical Gospels.
Worship services on Palm Sunday include a procession of the faithful carrying palms that represent the palm branches the crowd scattered in front of Jesus as he rode into Jerusalem in In Episcopal, Catholic, other denominations and in the Ethiopian Orthodox Church. The problem of procuring palms in unfavorable climates led to their substitution with branches of native trees, including yew, willow, olive and box. The Sunday was sometimes named after these substitute trees like in Yew Sunday or by the general term Branch Sunday.