This analysis considers validly published binomial species names (excluding hybrids) in the World Checklist of Vascular Plants (WCVP) v12 [1] that resolve to an accepted name (i.e. Unplaced names are ignored). We consider duplicated binomial names as homonyms, and specifically explore ambiguous homonyms ( i.e. those that resolve to different accepted species).
Out of the 958,654 species records in the WCVP, 57,767 of these are species binomials that are ambiguous homonyms. The breakdown of the taxon statuses of these 57,767 records is given below.
Out of 924,458 unique binomial species names in the WCVP, 26,588 of these are ambiguous homonyms.
The most common homonym is Artemisia rupestris, and this is also the binomial name that can refer to the most different accepted species, possibly referring to:
- Artemisia alba subsp. alba
- Artemisia atrata Lam.
- Artemisia granatensis Boiss.
- Artemisia norvegica subsp. norvegica
- Artemisia pedemontana subsp. assoana (Willk.) Rivas Mart.
- Artemisia rupestris L.
- Artemisia splendens Willd.
- Artemisia umbelliformis subsp. umbelliformis
The graph below shows published names over time and the proportions of which are homonyms (note that a name may have not been homonymous at publication but falls into homonymy due to a later publication). It is clear to see that over time, fewer homonyms are being published! This is somewhat unsurprising due to the connectivity given by the internet, as well as better nomenclature standards and name databases like IPNI.
The chart below shows the global distributions of the accepted species that are resolved to by ambiguous binomial homonyms. This may partly reflect the global distribution of plant species (e.g. dense population in South America --- see WCVP species plot), but parts of Europe are possibly over-represented.
The ambiguous homonyms discussed can be disambiguated by using the correct authority, e.g. Artemisia rupestris Scop. only refers to Artemisia alba subsp. alba, and so the presence of homonyms on their own is not necessarily an issue. However, these binomial names are not always disambiguated in this way and can result in ambiguity in scientific literature.
As seen above, the naming of plant species is improving over time with regards to homonymy. However, we wonder how ambiguous homonyms are treated in scientific literature and aim to quantify the number of ambiguous uses in scientific articles from CORE [2].
To do this, we search the 32.8 million full text papers hosted by CORE (v.2022) from 10,744 providers. For a given text, we begin by applying some simple cleaning which aims to extract the body text from the full text (i.e. the text given before 'References', 'Supplementary material', 'Conflict of interest' and 'Acknowledgments' headings) and then cleans the text by removing any punctuation (except hybrid characters "×" and "+"), setting all letters to lower case and single-spacing all whitespace. With this body text, we then search for mentions of any ambiguous species binomials (as defined above).
In papers containing these homonyms, we then search for any terms that potentially dismbiguate the homonym i.e.
- taxon names with authors
- taxon names with paranthet authors
- taxon names with primary author
- Each of the above with an abbreviated genus name.
we also check for the use of the homonym preceding infraspecific or hybrid characters which may indicate a disambiguation.
When searching for disambiguating terms, we clean the text as described above but without removing any sections. To align with the cleaned text, the disambiguating terms are also cleaned by removing any punctuation (except hybrid characters "×" and "+"), setting all letters to lower case and single-spacing all whitespace.
Results to follow...
[1] Rafaël Govaerts et al., ‘The World Checklist of Vascular Plants, a Continuously Updated Resource for Exploring Global Plant Diversity’, Scientific Data 8, no. 1 (2021): 1–10, https://doi.org/10.1038/s41597-021-00997-6.
[2] Petr Knoth et al., ‘CORE: A Global Aggregation Service for Open Access Papers’, Scientific Data 10, no. 1 (7 June 2023): 366, https://doi.org/10.1038/s41597-023-02208-w.
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