Families of Vascular Plants - EEB337H1

What is an authority?


The name of every plant group, e.g. order, family, genus, species, and subspecific taxon (subspecies, variety, or form) is associated with an authority, that is, the name of the botanist who first described it. The species authority, for example, is found usually in abbreviated form immediately after the species name. Sometimes more than one authority is associated with a taxon. For example, consider the name Strophostyles helvola (L.) Elliott. Linnaeus described Phaseolus helvolus. Elliott took this species out of Phaseolus and placed it in a new genus, Strophostyles, that he had described. The parenthetical authority is thus the one responsible for first using the name in question. Another combination of authorities that is seen indicates the publication by one person of a name that they ascibe to another, as in Crataegus succulenta Schrader ex Link. Here, the name succulenta was first used by Schrader, but was validly published only by Link.

Details of how and why authorities for the scientific names of plants are cited can be found in most textbooks of plant taxonomy, such as the one by Radford et al. (1974), or in Appendix 1 of the Judd et al. (2008) textbook. Many floras, manuals, and checklists (e.g. Muskoka Flora, from which this text is adapted) provide lists of authority abbreviations together with the complete names (and sometimes biographical and other information) of the individuals concerned. The standard list of author names and their abbreviations can be accessed on the International Plant Names Index (IPNI) web site.


| What are plant families? | How do we distinguish them? | How and why do we study them? | Selected vascular plant families of Ontario | Reading List | Course outline |

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