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

Callithamnion tetricum (Dillwyn) S.F.Gray

Botany

Taxonomy

Algues 200
Callithamnion 200

200 Specimens registered in collections

Collection Number of specimens (or sets)
Cryptogams (PC) 199
Herbarium of harmas de J. H. Fabre (FABR) 1

Callithamnion tetricum C.Agardh

Botany

Taxonomy

Algues 31
Callithamnion 31

Specimens registered in collections

Collection Number of specimens (or sets)
Cryptogams (PC) 31

Callithamnion tetricum (Dillwyn) S.F.Gray

Zoology

Taxonomy

Algues 7
Callithamnion 7

Specimens registered in collections

Collection Number of specimens (or sets)
Marine Laboratory of Concarneau (CO) 7