lesser clubmoss vs spike moss

lesser clubmoss

noun
  • Selaginella selaginoides, a vascular plant of the family Selaginellaceae that resembles moss and is widely distributed in the Northern Hemisphere. 

spike moss

noun
  • Any of various simple vascular plants, of the family Selaginellaceae, that resemble mosses and produce spores. 

How often have the words lesser clubmoss and spike moss occurred in a corpus of books? (source: Google Ngram Viewer )