Together with species delimitation, a significant part of taxonomic revision involves establishing the validity and priority of names. Usually the aim is to have one accepted name per taxon but where there are fewer epithets than species, then new names need to be generated and published. Much more frequent, however, is the case of several epithets being associated with a single species and in these cases one of the epithets has to be selected as the accepted name . The remaining names are designated as synonyms. Within botany there are on average three epithets associated with each name.
In order to ensure the stability of this process names and their application is regulated by a code called the International Code of Botanical Nomenclature . The code defines valid publication through a series of Articles and historical priority as well as the place and nature of the material published are all important criteria. Applying the code inevitably involves having to check publications from the 18th, 19th and 20thC, many of which exist in only a handful of libraries. This can be fiddly and time-consuming but also fascinating and rewarding . Up until a few years ago you would need access to a very good botanical library, herbarium and probably loans of type specimens. This made the task a real challenge for botanists not based in a small number of mainly European and North American institutions.
Fortunately the botanical community has come together to digitize and make available their libraries, specimens and databases of names and it is now possible, in many cases, to look at specimens from Lamarck’s herbarium in Paris, the Denmark Natural History Museum or Rio de Janeiro Botanical Garden and a rare book from the 18thC in the Natural History Museum or the Missouri Botanical Garden and compare dates and places of publication with the Smithsonian’s index to plant genus names, all from your desk-top and in less than an hour. A task which could have taken weeks only a decade ago.
Below are online resources that I have found most useful:
The International Code of Nomenclature for algae, fungi and plants, as described above this is the code that regulates how we associate and validly publish species epithets. It also regulates how we evaluate and assign priority to synonyms.
Index Nominum Genericorum, a compilation of generic names published for organisms covered by the International Code (above). This represents a synthesis of information on places of publication dates, types and nomenclatural status. Whilst not completely free of errors it is a very valuable source of information that also feeds in outputs from the The International Plant Names Index (IPNI) and TROPICOS on-line resources.
The International Plant Names Index (IPNI) is a database of the names and associated basic bibliographical details. Its goal is to eliminate the need for repeated reference to primary sources for basic bibliographic information about plant names. IPNI is the product of a collaboration between The Royal Botanic Gardens, Kew, The Harvard University Herbaria, and the Australian National Herbarium. While there are a few errors in bibliographic citation and it only provides bibliographic citations it is a very comprehensive resource.
TROPICOS is a synthesis of all of the nomenclatural, bibliographic, and specimen data accumulated in Missouri Botanical Garden’s electronic databases. This system has over 1.2 million scientific names and 4.0 million specimen records. While there are a few errors in bibliographic citation and not all species names are present this is compensated for by its ability to bring together links to scans of the original publications for a name, specimens, images and floristic publications which cite the name. A very impressive and invaluable resource for the botanical community Worldwide. Particularly strong on the Americas, China and Madagascar.
The Biodiversity Heritage Library (BHL) is a consortium of natural history and botanical libraries that cooperate to digitize and make accessible the legacy literature of biodiversity held in their collections as a part of a global “biodiversity commons.” This is a very useful resource , sometimes a search will return two or more seemingly identical results, these should both be explored as they will often be for distinct publications .
Global Plants is a community-contributed database that features more than two million high resolution plant type specimen images and other foundational materials from the collections of hundreds of herbaria around the world. Whilst not open access it is accessible from most academic institutions. The attribution of type specimens is unreliable and you should not use this as a source for type attribution. However if you know what the type collection you are looking for is then this can be a good place to find it.
The Natural History Museum Paris digitized specimen database is a very useful resource if you are looking for a type collection that is not on Global Plants (see above). The Paris herbarium is likely the largest in the World and includes many very important historical collections such as Lamarck and Jussieu. The portal is not very user-friendly and I would recommend only including the species binomial for which you are seeking a type and then filtering the results by scientific name. This is because although all the collections are available, not all have had their meta data uploaded and so filtering can exclude the specimens you are looking for only because their meta data has not been databased.
Linnean Plant Names is a searchable database containing typification details for all Linnaean plant names. Where relevant, detailed notes are provided to account for published observations that may fall short of formal typification. The content of the database has been meticulously compiled. Linnaeus published over 9,000 plant names hence the importance of this site. This is probably the most reliable of all online resources.