noonflower vs pebble plant

noonflower

noun
  • Flowers of the genus Bauhinia. 

  • Flowers of the family Aizoaceae, especially those of the genus Carpobrotus. 

  • Tragopogon, a type of aster that closes at midday. 

pebble plant

noun
  • A lithops (succulent plant of genus Lithops) 

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