I’m confused what to do with the Himalayan Blackberry observations in California.
[I intentionally used only the common name in that sentence.]
It appears there is confusion regarding the common name: “Himalayan Blackberry” and the species: Rubus armeniacus and Rubus bifrons, at least with the west coast observations. I am guessing this happened because they share a common name. If you Google: “Himalayan blackberry California” you get many matches that give you the Himalayan Blackberry, Rubus armeniacus. There are significant sources that treat R. armeniacus and R. bifrons as synomyms.
Because major sources treat these names as synonyms including Jepson eFlora and Flora of North America, my practice has been to identify these blackberries as R. armeniacus unless they already had an idenfication of R. bifrons; in those cases I would merely “agree”.
However, another iNatter has provided information that challenges the possibility that they are synonyms and that they are indeed separate species but only R. armeniacus occurs in California.
@lehacarpenter provided these links:
Of note, the FEIS-USDA page asserts that R. armeniacus “is considered the most invasive nonnative shrub on the West Coast” whereas “Rubus bifrons is not considered highly invasive.”
Now I suspect every time I agreed with an observation of R. bifrons I was making a mistake and I should have instead used R. armeniacus. I wonder if all the California R. bifrons observations are incorrect and are R. armeniacus instead.
I can only speculate but I suspect many were misidentified this way because the user was choosing the common name: “Himalayan Blackberry”.
If most of the “Himalyan Blackberry” plants in the United States are the invasive R. armeniacus and only a few are the not-as-invasive R. bifrons shouldn’t iNaturalist have used “Himalayan Blackberry” for R. armeniacus instead? To avoid confusion, should the name “Himalayan Blackberry” be removed from R. bifrons? A vast majority (maybe 85%) of the R. bifrons observations are in the western part of the United States and Canada. All of these are likely R. armeniacus. Only 10% of the R. bifrons observations are in the eastern parts of the United States where the USDA says R. bifrons exists.
Should I go back and change all my previous R. bifrons identifications to R. armeniacus? Usually, I only do these ids in California and Oregon.
I do not know what to say about the few states where the USDA says the two species overlap.
For additional reference, here are the distribution maps from the USDA plants database: