''Tetraedron'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alg ...

in the family

Hydrodictyaceae Hydrodictyaceae is a family of green algae in the order Sphaeropleales. Genera * ''Euastropsis'' * '' Helierella'' * ''Hydrodictyon'' * '' Lacunastrum'' * ''Monactinus'' * ''Parapediastrum'' * '' Pediastrum'' * ''Pseudopediastrum'' * ''Sorastr ...

Species list

* '' T. acutum'' * '' T. arthrodesmiforme'' * '' T. bifurcatum'' * '' T. caudatum'' * '' T. conicum'' * '' T. constrictum'' * '' T. cruciatum'' * '' T. cruciforme'' * '' T. curvatum'' * '' T. gigas'' * '' T. gracile'' * '' T. granulosum'' * '' T. hastatum'' * '' T. hortense'' * '' T. incus'' * '' T. limneticum'' * '' T. lobulatum'' * '' T. longispinum'' * '' T. minimum'' * '' T. minutissimum'' * '' T. minutum'' * '' T. muticum'' * '' T. obtusum'' * '' T. octaedricum'' * '' T. pachydermum'' * '' T. planctonicum'' * '' T. proteiforme'' * '' T. pusillum'' * '' T. rectangulare'' * '' T. regulare'' * '' T. reticulatum'' * '' T. simmeri'' * '' T. staurastroides'' * '' T. striatum'' * '' T. triangulare'' * '' T. trigonum'' * '' T. trilobatum'' * '' T. tumidulum'' * '' T. vulgare'' * '' T. wasteneysii''

References

Sphaeropleales genera Sphaeropleales {{Chlorophyceae-stub