Phycomycetes group vs taxon

Phycomycetes group and taxon both are nouns.

Word	Noun	Adjective	Verb	Adverb
Phycomycetes group	Yes	No	No	No
taxon	Yes	No	No	No

As nouns, taxon is a hypernym of Phycomycetes group; that is, taxon is a word with a broader meaning than Phycomycetes group:

Phycomycetes group: a large and probably unnatural group of fungi and funguslike organisms comprising the Mastigomycota (including the Oomycetes) and Zygomycota subdivisions of the division Eumycota; a category not used in all systems
taxon: animal or plant group having natural relations

Other hypernyms of Phycomycetes group include taxonomic category, taxonomic group.

Phycomycetes group (noun)	taxon (noun)
a large and probably unnatural group of fungi and funguslike organisms comprising the Mastigomycota (including the Oomycetes) and Zygomycota subdivisions of the division Eumycota; a category not used in all systems	animal or plant group having natural relations