common reed vs walking stick

common reed

noun
  • Phragmites australis, a monoculture reed grass. 

walking stick

noun
  • A stick insect (order Phasmida). 

  • A tool, such as a cane, used to ease pressure on the legs, and to aid stability, when walking. 

  • A playing card with the rank of seven. 

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