Uvularia grandiflora vs strawflower

Uvularia grandiflora

strawflower

noun
  • Any of many Australian plants of the genus Xerochrysum, especially Xerochrysum bracteatum, having deep yellow flowers than can be readily dried. 

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