Acacia - (Easton's Bible Dictionary)
(Heb. shittim) Ex. 25:5, R.V. probably the Acacia seyal (the gum-arabic tree); called the "shittah" tree (Isa. 41:19). Its wood is called shittim wood (Ex. 26:15, 26; 25:10, 13, 23, 28, etc.). This species (A. seyal) is like the hawthorn, a gnarled and thorny tree. It yields the gum-arabic of commerce. It is found in abundance in the Sinaitic peninsula.