[1] Bessey based his system on the tradition of de Candolle, Bentham and Hooker and Hallier.
He taught that taxonomy must be based on evolutionary principles.
He considered Spermatophyta as having a polyphyletic origin, being composed by three different phyla, of which he only treated Anthophyta (syn.
In that he used the same names for the subclasses of both monocotyledons and dicotyledons, this is contrary to contemporary rules on plant nomenclature that require names to be unique.
However Bessey actually used a qualifying hyphenation (Alternifoliae-Strobiloideae and Oppositifoliae-Strobiloideae), a distinction not always recognised in reference to this scheme.