amaranthus vs portulaca

amaranthus

noun

  • Any of the genus Amaranthus; an amaranth. 

portulaca

noun

  • Any plant in the genus Portulaca 

  • Any of many tropical trailing herbs, of the genus Portulaca, having showy flowers 

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