sugar cane vs sugarcane

sugar cane

noun
  • A tropical grass of the genus Saccharum (especially the species Saccharum officinarum, including hybrids) having stout, fibrous, jointed stalks, the sap of which is a source of sugar. 

  • A candy cane, an edible candy in the shape of a cane. 

sugarcane

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