There are four species of true cedar, which are ornamental and timber conifers of the genus Cedrus, in the pine family. Three of those are native to mountains of the Mediterranean region, the fourth to the Himalayas. But many other conifers are known as cedars, those that look similar, with a strong aroma and reddish bark that is often decay-resistant and insect-repellent.

Cedar sawdust has been found in Egyptian tombs, and its resin was used in mummification. Because cedars come from the birthplace of western religion, they are freighted with symbolic meaning, especially the Cedar of Lebanon, and they are mention often in the bible. In the Epic of Gilgamesh, the cedar groves of Lebanon are the home of gods to which Gilgamesh journeys. More generally cedars are associated with ritual and cleansing.

Interestingly, the red cedar (not a true cedar) which is found in the American east is often one of the first trees to colonize cleared landed, which might suggest it as a symbol of renewal.

In Faulkner's work, cedar trees are often associated with grave sites (decay-resistant), and seem symbolic of the power the dead and the past holds over the living. The characters of the novels enter the groves with hesitation, if not trepidation. In light of the reverence they receive, it seems significant that other characters work in saw mills: for example, while Joana Burden discuss the strange power the cedar around her family's grave site holds over her, Joe Christmas shovels sawdust. Their tension is manifested even in trees.

[Ed. Question: What kind of trees does Caddy climb/sit under with Charline in TSATF?]

Sources:

http://forestry.about.com/od/conifers/tp/Eastern_Redcedar.htm

"cedar." Encyclopaedia Britannica. Encyclopaedia Britannica Online Academic Edition. Encyclopædia Britannica Inc., 2013. Web. 20 Dec. 2013.

http://en.wikipedia.org/wiki/Cedrus_libani

-Nick Neely

From AA:

"... [Quentin] looked up the slope before them where the wet yellow sedge died upward into the rain like metling gold and saw the grove, the clump of cedars on the rest of the hill dissolving into the rain as if the trees had been drawn in ink on a wet blotter ..." (AA 153)

"Quentin had to stoop and brush away some of the cedar needles to read the next one [grave marker]." (AA 155)

"It must have resembled a garden scene by the Irish poet, Wilde: the late afternoon, the dark cedars with the level sun in them, even the light exactly right and the graves, the three pieces of marble […] looking as though they had been cleaned and polished and arranged by scene shifters who with the passing of twilight would return and strike them and carry them, hollow and fragile and without weight, back to the warehouse until they should be needed again […]” (AA 157).

From LIA:

"She [Joana Burden] told Christmas about the graves--the brother's, the grandfathers, the father's and his two wives--on a cedar knoll in a pasture a half mile from the house ..." (LIA 248)

"I [Joana] didn't want to go into the cedars ... I think it was something about father, something that came from the cedar grove to me, through him. A something that I felt that he had put on the cedar grove, and that when I went into it, the grove would put on me so that I would never be able to forget it." (LIA 252).