Flag for Taxon: low pricklypear (Opuntia humifusa)

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Flag for Taxon: low pricklypear (Opuntia humifusa)

Flagger	Content Author	Content	Reason	Flag Created	Resolved by	Resolution
reuvenm		low pricklypear (Opuntia humifusa)	common name issue - see comments	May. 10, 2018 00:50:55 +0000	Not Resolved

Comments

There are three taxa with common names that are some minor variation on Eastern Prickly Pear:
https://www.inaturalist.org/taxa/47894-Opuntia-humifusa
https://www.inaturalist.org/taxa/553158-Opuntia-cespitosa
https://www.inaturalist.org/taxa/241849-Opuntia-humifusa-humifusa

This clearly needs to be cleaned up but I'm not sure the best way to do so and hoping someone else has the expertise.
@wdvanhem

Posted by reuvenm almost 6 years ago

This issue goes beyond common names. O. cespitosa is a relatively new taxon, formerly lumped in O. humifusa, and not yet acknowledged by all references. Here's a summary:

Accept O. cespitosa:
VASCAN

Do not accept O. cespitosa:
FNA
USDA
ITIS
BONAP

The only regional floras that accept O. cespitosa in place of O. humifusa seem to be NHIC (Ontario) and Michigan Flora.

Even in the literature there seems to be disagreement about the status of O. cespitosa. Particularly since the morphological distinction between the two species is pretty blurry. See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3833768/

In short...I'm not sure I agree that O. cespitosa should even be in iNat's taxonomy, since most authorities still consider our (Ontario) plants to be O. humifusa. I'm by no means an expert on the taxon so I'd be interested in hearing what others say.

Posted by wdvanhem almost 6 years ago

Maybe @lincolndurey or @bouteloua have some thoughts on this. Not sure who the Opuntia experts are on iNat.

Posted by wdvanhem almost 6 years ago

lump it!

(disclaimer: i am not an opuntia expert. There are two similar ones in California that definitely seem to intergrade though)

Posted by charlie almost 6 years ago

For O. cespitosa, of the iNat authorities for vascular plants,

GoBotany--accepted, see sidebar
VASCAN--accepted
Weakley--accepted
Calflora--not treated (does not range into California)
The Plant List--not treated; the spelling O. caespitosa is listed as unresolved.

-----end iNat authorities-----

See also:
A more recent paper by Majure (2017).
Plants of the World Online, which iNat is likely to move to once more complete--accepted
And accepted in our Flora of the Chicago Region (2017).

The authors of Flora of the Chicago Region call it "eastern prickly pear." Weakley calls it "common eastern prickly pear" and calls O. humifusa "eastern prickly pear." VASCAN calls it "eastern prickly-pear cactus."

Not sure there's really a good way around the doubled-up common names. They need to both show up when someone types "eastern prickly pear."

Posted by bouteloua almost 6 years ago

Weakley's Flora 2015 (pretty much THE freely available key ref for the SE, but that I use outside that region) accepts O.cespitosa "Common Eastern Prickly-pear", and goes into some length (p847-849) to key it out from O.humifusa by several characters we should be able to see in iNat images., perferred habitats and locations are discussed. as are the potential progenitor species.

Sadly, it looks as tho most of our O.humifusa IDs are wrong, and should be O.cespitosa (based on range), someone would have to dig them out as I did with Nuphar... ... ...
@whiteoak

Posted by lincolndurey almost 6 years ago

Sounds like a split that's here to stay.

As for common names, while having Eastern Prickly Pear as an alternate common name is fine, I think having two similar species in the same area with the same default common name is extremely confusing to the average person. I wish anybody involved with this taxonomy or the floras had thought to deal with the common name problem, but it doesn't appear anybody has...

Not sure what the best way forward for us is. As far as I can see, neither species seems to have ever been referred to by anything besides Eastern Prickly Pear or some slight variation since the split.

Posted by reuvenm almost 6 years ago

If the split is here to stay, then Ontario plants are for sure O. cespitosa. Outside of Ontario we will have to clean them up. I'm indifferent to the common name...could be something like Cespitose Prickly-pear for O. cespitosa or Northern Prickly-pear (since it seems to have a more northern distribution).

Posted by wdvanhem almost 6 years ago