Flag for Taxon: dogwoods (Genus Cornus)
| Flagger | Content Author | Content | Reason | Flag Created | Resolved by | Resolution |
|---|---|---|---|---|---|---|
| gwark | dogwoods (Genus Cornus) |
it may be worth adding Subgenus Arctocrania for the 'dwarf dogwoods' |
Aug. 4, 2020 01:26:27 +0000 | upupa-epops |
subgenus added |
Comments
This sounds like a good idea. Phylogeny of genus Cornus is presented here, and this subgenus is well supported:
Xiang, Q. Y., Thomas, D. T., Zhang, W., Manchester, S. R., & Murrell, Z. (2006). Species level phylogeny of the genus Cornus (Cornaceae) based on molecular and morphological evidence—implications for taxonomy and Tertiary intercontinental migration. Taxon, 55(1), 9-30.
I just want to add my agreement to @gwark's proposal. I think that it would be useful for on several levels:
It would offer greater precision in IDs for computer vision
It would offer an more satisfying ID than going up to the genus & lumping an observation in with various woody shrubs & trees
It would allow those trying to offer species IDs a more narrowly defined group to examine
In addition to the 2006 paper cited by @naokitakebayashi, there's this one from 2001 in Am J Bot 2001 Jun;88(6):1131-8: Phylogenetic relationships within Cornus (Cornaceae) based on 26S rDNA sequences | DOI: 10.2307/2657096
In particular, Figure 3 from the paper makes for a very compelling division of the subgenus:
Edited to add: eFloras also mentions the subgenus: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=316357
I agree 100% with the comments above. I've been actively trying to accurately ID the bunchberries on iNat over the past year with moderate success, but all too often the best ID winds up as Genus Cornus. This is often due to hybrids that share characteristics between C canadensis, C unalaschkensis, and C suecica, as detailed in Murrell's 1994 paper. Dwarf Dogwoods: Intermediacy and the Morphological Landscape.
Should the other subgenera be added as well?
I'd be in favour of that, @upupa-epops. While it would probably offer the greatest help to those of us identifying Dwarf Dogwoods, I cannot see how it would negatively affect any of the other species. For identifying within my province, it might be helpful for giving a narrower ID for exotic dogwood species often brought in as ornamental plants.
Is there a good resource that lists what subgenus every species in the genus is in?
One might need to go through the paper linked by @naokitakebayashi and possibly the references within it.
@upupa-epops, I have an organized list that should be 95% of the way there. I was thinking of adding it as a "wiki" post in the Forum so we could do this collaboratively. Would that be helpful to you?
@murphyslab that list would definitely be helpful! I'm not sure if the forum is the best place for it though since that would be sent publicly to everyone. For organizing Salix we used a Google Sheets document, would that work?
The list includes notes & it's already entirely in markdown. I'm not quite sure what risk there is, since the taxon flag and comments are all public too.
Sorry, it's not that I'm concerned about people seeing it, I just mean the type of content that the forum is meant for. Anyway, you can try posting it there and we'll work it out.
Fair enough, @upupa-epops. Also I just read tiwane's intro on the Curators category and the bold imperative: "This is not a place to discuss possible changes to specific taxa." Although I really do think that as a tool, a wiki-style forum post would be perfect for this kind of stuff.
Just so I don't clog-up this flag thread, I just pasted what I have into a journal, although if it works better I can just paste it here:
https://www.inaturalist.org/journal/murphyslab/54733-sorting-the-genus-cornus-into-subgenera
There are 3 regular species for which I can't find a subgenus, although it can probably be determined by key. Also 2 inter-clade hybrids that probably don't have a home subgenus.
Great to see this request is finally getting somewhere. Thanks to @gwark for getting the ball rolling, and to @murphyslab for better defining the process. @murphyslab please include me on your list of reviewers.
It would be nice to have a place to put the other big bracted hybrids in addition to x rutgersensis. There have been dozens and dozens of observations of kousa x nuttallii, florida x nuttallii, and even more complex hybrids. Like the bunchberry hybrids, it seems a shame to dump them in Genus Cornus.
No opposition from me.
Hey everyone, sorry I've been busy the past couple months. I've created the subgenera listed in @murphyslab's journal and will start adding the species into them now.
Just looking at the taxonomy I have to wonder why it has been designated Genus > Clade > Subgenus for Cornus rather than Genus > Subgenus > Section. If it was the latter than we could include the intermediate level on iNaturalist which seems like it could be useful.
Finished!
Let me know if you see any mistakes or other changes that need to be made.
I had a look at the species lists under each of the subgenera and all of them appear to be correct and complete.
Thanks a bunch(berry), @upupa-epops !
C. canadensis, C. suecica, and C. unalaschkensis would be within this subgenus. There are intermediate forms which have mostly been lumped into C. unalaschkensis (assuming they're not misidentified as C. canadensis, as often seems to be the case) - but strictly speaking, that might not be the best option. If this subgenus were available, it would offer an alternative option when it's clear that the observation is of a dwarf dogwood, but it's not a great fit for any of the three species in the this group (which is easily differentiated from the rest of the genus).