Abstract
Excerpt: The April issue of Nature Plants featured an editorial (Nature Photoaerogens?)1 addressing my proposal of the term photoaerogen to refer to cyanobacteria, eukaryotic algae and plants collectively. Of course I was thrilled that my essay2 received such high-profile attention. But I also felt that the editorial frequently misses the point. Its subtitle and first paragraph highlight, with amusing anecdotes, the difficulties and fundamental arbitrarity of classification systems. Yet my essay made no suggestions regarding classification or biosystematic nomenclature. Photoaerogen was explicitly proposed as a term without taxonomic implications. While some biological concepts group organisms biosystematically according to phylogenetic affinities, others recognize common functional or ecological properties regardless of phylogen.
