abaxial vs dorsumal

abaxial

adj
  • Of a side that is facing away from the axis or central line, such as the underside of a leaf; or the back of an animal. 

  • Not in the axis. Applied to an embryo placed out of the axis of the seed. 

dorsumal

adj
  • Synonym of dorsal 

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