Rubus nutkanus? For those familiar with this species, you’ll probably be wondering what justifies the change in name of thimbleberry from Rubus parviflorus.
Rubus parviflorus is a head-scratchingly deceptive name for this entity: parviflorus means “small-flowered”, yet this species actually has some of the largest flowers within Rubus. This wouldn’t justify the change in name, however–there is nothing in the International Code of Nomenclature for Algae, Fungi, and Plants that mandates that an epithet be descriptively appropriate (though there is an implied recommendation). And, looking at the original publication where Rubus parviflorus Nutt. was named, it is apparently described from a small-flowered specimen.
What The Code does assert, though, is the concept of priority: the first validly-published and legitimate name for a species is the one that should be used (allowances are made for some practical exclusions to this concept). The problem with Nuttall’s 1818 publication and use of Rubus parviflorus is that the name was used in 1770 by Weston and applied to an entity now determined to be Rubus creticus. Even though Weston’s use of Rubus parviflorus has long fallen into a synonymy footnote, its existence predating Nuttall’s assignment of the name means that Nuttall did not legitimately use the name.
Going back to the The Code and its requirements, the first validly-published and legitimate name for this species is the published-in-1825 Rubus nutkanus Moc. ex Ser.. This was the conclusion of Van De Beek’s 2016 article, Validations of the Rubus taxa in Tournefort’s Institutiones and their Corollarium in later literature. In agreement with Van De Beek, Rubus nutkanus is the name being used in the upcoming Flora of the Pacific Northwest, 2nd Edition (pre-order USA, Canada, and UK and Europe). If you are still unconvinced, note also it is now the name used by Royal Botanic Gardens, Kew on its Plants of the World Online site.
As you may note from the link to the Kew site above, Rubus nutkanus is native to much of western North America, parts of southeastern Asia, and parts of central and eastern North America. In western North America, it is widespread, while in the eastern part of the continent it is “discontinuously distributed” in non-arid habitats. Like many species of Rubus, it can be invasive when introduced into a non-native area–hence its presence in parts of Europe.
Few other references, if any, have adopted Rubus nutkanus. Whenever you see Rubus parviflorus in the following set of resources, think Rubus nutkanus: