shittah vs shittah tree

shittah

noun
  • The wood of this tree. 

  • A tree said in the Bible to have furnished the precious wood of which the ark, tables, altars, boards, etc., of the Jewish tabernacle were made; now believed to have been the red acacia, Acacia seyal, now Vachellia seyal. 

shittah tree

How often have the words shittah and shittah tree occurred in a corpus of books? (source: Google Ngram Viewer )