common reed vs molasses cane

common reed

noun
  • Phragmites australis, a monoculture reed grass. 

molasses cane

noun
  • A plant, commonly sugar cane, maize/corn, sorghum (maize or milo), or other another fructose-producing grass plant (of the family Gramineae) used for production of cane syrup or molasses. 

How often have the words common reed and molasses cane occurred in a corpus of books? (source: Google Ngram Viewer )