In zoological nomenclature, a subphylum is a taxonomic rank below the rank of phylum. The taxonomic rank of "subdivision" in fungi and plant taxonomy is...

(in botany) Infraphylum, or infradivision (in botany) Parvphylum or microphylum Superclass Class Subclass Infraclass Subterclass Parvclass Superdivision...

plants that also use this method include Potamogeton species and some Microphylum species. The lack of flow in ponds provide habitats for plants that are...