Several names share this combination and are defined under the rules of the botanical code. The species name Callithamnion tetragonum might be an homonymy case.
The name Callithamnion tetragonum is a slight homonymy case. This name is used according to the rules of several different nomenclatural codes.

Callithamnion tetragonum C.Agardh

Botany

Taxonomy

Algues 17
Callithamnion 17

Specimens registered in collections

Collection Number of specimens (or sets)
Cryptogams (PC) 17

Callithamnion tetragonum (Withering) S.F.Gray

Botany

Taxonomy

Algues 161
Callithamnion 161

Specimens registered in collections

Collection Number of specimens (or sets)
Cryptogams (PC) 161

Callithamnion tetragonum (Stackh.) C.Agardh

Botany

Taxonomy

Algues 4
Callithamnion 4

Specimens registered in collections

Collection Number of specimens (or sets)
Cryptogams (PC) 4

Callithamnion tetragonum (Stackh.) C.Agardh

Zoology

Taxonomy

Algues 16
Callithamnion 17

Infraspecific ranks

Callithamnion tetragonum var. brachiatum (Bonnem.) J.Agardh 1 1

Specimens registered in collections

Collection Number of specimens (or sets)
Marine Laboratory of Concarneau (CO) 17