snow-on-the-mountain vs variegated spurge

snow-on-the-mountain

noun
  • A small shrub in the family Euphorbiaceae, having white-margined leaves and white flowers; Euphorbia marginata. 

variegated spurge

How often have the words snow-on-the-mountain and variegated spurge occurred in a corpus of books? (source: Google Ngram Viewer )