Taxonomy of Dewberries, Blackberries, and Brambles in Texas (Rubus spp)



This post is Part 1 of my series on Rubus species in Texas.
Part 2 - Key to Rubus spp of Texas (Dewberries, blackberries, and brambles)
Part 3 - Rubus spp (of Texas) comparison of features



I have basically identified my Rubus observations as R. trivialis or R. oklahomus, but I was aware there were other possibilities that I should look into. I've been looking closer at Rubus species in Texas this past 2 weeks. This journal post will walk through the musical score that is Rubus taxonomy yesterday, today, and tomorrow in Texas.

YESTERDAY
The Flora of North Central Texas, aka FNCT, (the primary flora key for DFW) listed 6 possible species in DFW: aborignium, apogaeus, bifrons, oklahomus, trivialis, and riograndis. iNat observations were in 14 species, so I knew we had some errors. I looked at all 14 species on BONAP to see which of those 14 were not documented in Texas at all. I manually added genus level IDs and comments to those (DFW) observations with the link to the map. Afterward, I went back and reviewed all of Texas observations and did the same for those.

I'll note here that if you upload an observation of a Rubus species, the ID suggestions frequently come up with species not in Texas as a first choice. (Ex. R. armeniacus.) Typically only 1 of the top 5 species recommendations is in Texas. It may even say "Seen nearby" since so many were mis-ID'ed.

If you browse the species maps for Rubus on BONAP you will count 227 species in North America. I kid you not. Or maybe it was 229. Or 224. I lost count. Fortunately, not all of those are in Texas, though. (USDA Plants Database is in line with BONAP.)

So I wandered over to Flora of North America, aka FNA, to see what they had to say about it. I'll give you the short version here: "Rubus, especially the blackberries, presents some of the most difficult species-level problems, because of polyploidy, apomixis, and hybridization. As a result, differences of opinion on the number of species to be recognized from a given region can vary tremendously... R. K. Godfrey (1988) wrote, 'oversimplification appears to be the only way to achieve a practicable solution to the dilemma.'" (I'll agree with that!)

The FNA key lists about 25 species for all of North America. I looked at every single one and the distribution ranges to find all of the species in Texas. They only list FIVE: bifrons, flagellaris, pascuus, pensilvanicus, and trivialis.

Another hop over to Plants of the World Online, aka POWO, (which iNat uses to determine synonyms and currently accepted names) was aligned with FNA. (R. riograndis is treated as R. trivialis in FNA, but not in POWO, so that will be our 6th.)
Which brings me to...

TODAY
Here are a list of the synonyms and their currently accepted names for just the DFW species listed in FNCT:
R. aboriginum --> R. flagellaris
R. apogaeus --> R. flagellaris
R. bifrons --> No change
R. oklahomus --> R. pensilvanicus
R. trivialis --> No change
R. riograndis --> No change

These changes will bring iNat taxa in line with FNA and POWO and their state range maps, but it will require you to know the previous name to look at county maps on BONAP (which was last updated online in 2013/14.)

TOMORROW
You will begin to see some curation changes on iNat affecting Texas Rubus species, to bring us into agreement with FNA and POWO, as listed above.

To summarize, all of TEXAS only has 6 possible Rubus species:
bifrons,
flagellaris,
pascuus,
pensilvanicus,
trivialis, and
riograndis.

This means R. allegheniensis and R. fruticosis are not valid TX species under any source.

Any observations ID'ed otherwise would be 1) a species not in Texas according to the simplified species list of FNA and PONO, 2) a cultivar, or 3) an old synonym that needs to be curated to the simplified list.

As a next step, I hope to put together a VERY simplified illustrated guide to the 3 most common Texas species: R. trivialis, R. flagellaris, and R. pensilvanicus. The purpose will be to give a quick and dirty way to differentiate those, as well as suggestions on what photos would help for a species-level ID.

The quick key journal post is now published here:
https://www.inaturalist.org/journal/kimberlietx/30266-key-to-rubus-spp-of-texas-dewberries-blackberries-and-brambles

Posted by kimberlietx kimberlietx, June 15, 2019 03:57

Comments

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Posted by kimberlietx over 1 year ago (Flag)
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Wonderful, wonderful, wonderful!!! Tagging others that would find this helpful too:
@suz @sonnia @alisonnorthup @gcwarbler @nathantaylor @ellen5

Posted by sambiology over 1 year ago (Flag)
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Posted by kimberlietx over 1 year ago (Flag)
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Awesome job @kimberlietx !!!

Posted by nathantaylor over 1 year ago (Flag)
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Excellent!!! Thanks for all your research!

Posted by artemis224 over 1 year ago (Flag)
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At this moment I'm really glad we haven't got any Rubus around these parts

Posted by ellen5 over 1 year ago (Flag)
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Great job! I enjoyed your sharing this with me during your visit a week ago.

Posted by suz over 1 year ago (Flag)
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A+ work ! thanks - - - @cgritz , @oz4caster , @mertmack1

Posted by itmndeborah over 1 year ago (Flag)
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Great!

Posted by cgritz over 1 year ago (Flag)
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Wonderful detective work sorting this out! I will admit to having laughed when I saw that there might be 227 species or 25 species extant. I love the order of magnitude difference there. And I like the Godfrey quote - sometimes to make usable sense of something one has to simplify. Range maps are going to make more sense with six (or even 25) species than with 227 species some of which may or may not be reproductively isolated from each other.

Posted by danaleeling over 1 year ago (Flag)
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So, what ended up happening to riograndis? You have it still listed here but I saw elsewhere you mentioned it as merging with trivialis? I ask because I learned riograndis in college 20 years ago and want to make sure I'm not missing something here.

Posted by oceanicwilderness 8 months ago (Flag)
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@oceanicwilderness According to Flora of North America, riograndis is now a synonym of trivialis. Plants of the World Online, which iNaturalist follows for plant taxonomy, has not adopted that change yet, so they still show riograndis as a valid species name. It's kind of caught in the middle, as far as iNat goes. I recently added IDs to riograndis obsv in Texas with comments that it is now trivialis, but I can't flag for curation until POWO is updated.

Posted by kimberlietx 8 months ago (Flag)
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Posted by kimberlietx about 1 month ago (Flag)

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