Why is the Acacia a Masonic Symbol?

Acacia, an evergreen, is hardy and frequently sprouts from timbers of that species. Hence, the Jews planted Acacia on graves as a symbol of life and of the immortality of the soul.
(Source: http://www.pagrandlodge.org/programs/masedu/qa/51-67.html)
The Acacia or evergreen is a visual item used in Masonic Funerals. Allen Price

Scottish Rite Trivia

The thirty-three degrees of the Scottish Rite are conferred by several controlling bodies. The first of these is the Craft Lodge which confers the Entered Apprentice, Fellowcraft, and Master Mason degrees. Craft lodges operate under the authority of Grand Lodges, not the Scottish Rite. Although most lodges throughout the English-speaking world do not confer the Scottish Rite versions of the first three degrees, there are a handful of lodges in New Orleans and in several other major cities that have traditionally conferred the Scottish Rite version of these degrees.