achene vs nard

achene

noun
  • A small, dry, indehiscent fruit, containing a single seed, as in the buttercup. 

nard

noun
  • A fragrant oil from the plant, formerly much prized. 

  • Nardostachys jatamansi, a flowering plant of the valerian family that grows in the Himalayas, used as a perfume, an incense, a sedative, and an herbal medicine. 

  • A testicle. 

  • American spikenard (Aralia racemosa), a North American perennial herb with an aromatic root. 

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