In botanical nomenclature, the synonym of a botanical name is a name that also applies to this same taxon. A synonym cannot exist is isolation: it is always "a synonym of ...". In botany synonyms can be:

• homotypic (or nomenclatural): having the same type (specimen or illustration by which the species was named). The Linnaean name Pinus abies L. has the same type as Picea abies (L.) H.Karst. When the latter is taken to be the correct name (there is almost complete consensus on that), Pinus abies is a homotypic synonym of Picea abies. However, if the species were regarded to belong to Pinus (unlikely!) the relationship would be reversed and Picea abies would become a homotypic synonym of Pinus abies.

• heterotypic (or taxonomic): with a different type. Some botanists split the dandelion into many, quite small species. The name of each such species has it own type. When the dandelion is regarded as including all those small species, the names of all those species are heterotypic synonyms of Taraxacum officinale F.H.Wigg.

Note that in botany it is not required that a synonym has formal status ("be validly published"): a listing of synonyms often contains names that for some reason did not make it as a formal name (unpublished or manuscript names). Such a synonym must have the form of a formal name: it must look like a proper 'Latin name'.

Note also that a homotypic synonym need not share an epithet or name with the correct name, but only the type. For example the name Taraxacum officinale, mentioned above, has the same type as Leontodon taraxacum L. The latter is a homotypic synonym of Taraxacum officinale F.H.Wigg. The combination Taraxacum taraxacum is not acceptable, a tautonym.

Comparison with zoology

The treatment of synonyms in botanical nomenclature is quite different, in at least detail and terminology, from zoological nomenclature, where the correct name is included among synonyms, although as first among equals it is the senior synonym. What are synonyms in botany are junior synonyms in zoology.

What are homotypic or nomenclatural synonyms in botany are "objective synonyms" in zoology. What are heterotypic or taxonomic synonyms in botany are "subjective synonyms" in zoology.

See also

• synonym (zoology)
• basionym
• tautonym
• type (botany)
• synonym

Botany | Botanical nomenclature

Synoniem (taxonomie)