(Platythamnion) (Platythamnion) is a biological genus in the family Ceramiaceae and order Ceramiales.
Platythamnion heteromorphum
Platythamnion horridum
Platythamnion intermedium
Platythamnion orbigniana
Platythamnion pectinatum
Platythamnion recurvatum
Platythamnion reversum
Platythamnion tepocensis
Platythamnion villosum
Platythamnion yezoensis
Aglaothamnion
Anotrichium
Antithamnion
Antithamnionella
Bornetia
Callithamnion
Centroceras
Ceramium
Compsothamnion
Corynospora
Crouania
Griffitsia
Gymnothamnion
Haloplegma
Halurus
Hollenbergia
Lejolisia
Mesothamnion
Microcladia
Neoptilota
Platythamnion
Pleonosporium
Plumaria
Ptilota
Ptilothamnion
Ptilothamniopsis
Rhododictyon
Scagelia
Scagelonema
Seirospora
Spermothamnion
Sphondylothamnion
Spyridia
Tiffaniella
Trailliella
Wrangelia