“ It is significant that olive and willow should have been chosen for benediction together with, or as substitutes for palm, and that an exorcizing power should have been ascribed to the consecrated branches: they were to heal disease, ward off devils, protect the houses where they were set up against lightning and fire, and the fields where they were planted against hail and storms. But healing power had been ascribed to the olive in pagan antiquity, and in the same way the willow had from time immemorial been credited by the Teutonic peoples with the possession of protective qualities. ”

“ As the middle ages advanced the procession became more and more popular and increasingly a dramatic representation of the triumphal progress of Christ, the bishop riding on an ass or horse, as in the East. [3] Flowers, too, were blessed, as well as palms and willow, and carried in the procession (hence the names pascha floridum, dominica florum et ramorum les pâques fleuries) .
The origin of the ceremony of blessing the palms is more obscure. It is not essential to the dramatic character of the celebration and for centuries seems to have formed no usual part of it. ”

“ The ceremonies on Palm Sunday as celebrated now in the Roman Catholic Church are divided in three distinct parts: (1) The solemn blessing of the palms, (2) the procession, (3) the mass.
Branches of palm, olive or sprouting willow (hence in England known as “palm”) having been placed before the altar, or at the Epistle side, after Terce and the sprinkling of holy water, the priest, either in a purple cope or an alb without chasuble, proceeds to bless them. ”