"This Sunday, besides its liturgical and popular appellation of Palm Sunday, has had several other names. Thus it was called Hosanna Sunday, in allusion to the acclamation wherewith the Jews greeted Jesus on His entry into Jerusalem. Our forefathers used also to call it Pascha Floridum, because the feast of the Pasch (or Easter), which is but eight days off, is to-day in bud, so to speak, and the faithful could begin from this Sunday to fulfil the precept of Easter Communion. It was in allusion to this name, that the Spaniards, having on the Palm Sunday of 1513, discovered the peninsula on the Gulf of Mexico, called it Florida..."
http://www.liturgialatina.org/lityear/passion/palm_sun.htm 
