culm vs straw

culm

noun
  • the stem of a plant, especially of grass or sedge 

  • anthracite, especially when found in small masses 

  • waste coal, used as a poor quality fuel; slack. 

straw

noun
  • A dried stalk of a cereal plant. 

  • A pale, yellowish beige colour, like that of a dried straw. 

  • Such dried stalks considered collectively; this bulk matter may be a chief salable product, a by-product, fodder, bedding, or green manure, depending on region and on current market conditions. 

  • Anything proverbially worthless; the least possible thing. 

  • A drinking straw. 

verb
  • To lay straw around plants to protect them from frost. 

adj
  • Made of straw. 

  • Of a pale, yellowish beige colour, like that of a dried straw. 

  • Imaginary, but presented as real. 

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