Ilex cornuta 'Rotunda' × opaca: Chinese Holly escaped in upstate SC

General
1

Just so people know what I’m talking about, here’s I. cornuta in Weakley:
https://fsus.ncbg.unc.edu/main.php?pg=show-taxon-detail.php&lsid=urn:lsid:ncbg.unc.edu:taxon:{25D278D6-1FB8-4F6D-BCFA-70E618176A05}

Here’s Ilex opaca (American Holly):
https://fsus.ncbg.unc.edu/main.php?pg=show-taxon-detail.php&lsid=urn:lsid:ncbg.unc.edu:taxon:{34DB3AE0-297B-4B84-82FD-822985F16DDC}

I volunteer weeding invasives in the SC Botanical Garden and we see Ilex cornuta and Ilex cornuta × opaca seedlings popping up everywhere, especially near the base of mature Ilex opaca trees. I see them in shady areas around town and out in the woods. I didn’t see any such plants 5 years ago or an hour’s drive North or East. I think they are an emerging problem species.

Someone posted an Ilex opaca on iNaturalist yesterday and it came up for me to ID.
https://www.inaturalist.org/observations/271552662
It might be I. opaca, but it doesn’t look quite right to me. Not knowing whether to agree or disagree with their ID, I wrote a comment explaining the issue.

Here’s a more cornuta looking one:
https://www.inaturalist.org/observations/263196884

I think it would be helpful for land managers to be able to ID these as hybrids. Should we make an Ilex cornuta × opaca “species” here to determine what’s native to this area and what’s not? What’s the best way to handle this on iNaturalist?

2

Head to the taxon page for the genus and click “Curation”, then “Flag for curation”

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Done:
https://www.inaturalist.org/flags/753889
Thank you!

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4

Should I delete this post and put the information in that flag instead?

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5

I don’t think it needs to be deleted, but I’ve marked it as solved. It’s a good discussion to have on a taxon flag, so future discussion should take place there. You could also make a journal post on iNat and then link to it in a taxon flag or comments on observations as an easy way to spread awareness about the situation.

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I had thought too that it’s worth discussing how to handle these hybrids within the current system. Should they just be marked Ilex? Or should we pick which one they look more like (opaca vs. cornuta)? Or mark anything not obviously cornuta as opaca (largely what’s being done now).

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There is a subset of identifiers who will knock anything back to genus that isn’t an exact match.

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My question originated over casual comments made by knowledgeable people while out weeding invasive species. There is no published literature to support this supposed hybrid and the chromosome numbers of the parents are different, making it highly unlikely. Sorry to cause a fuss, but I appreciate that I got to learn something in the process.

I plan to ID these plants as their closest parent on iNaturalist. It looks like 5% of the Ilex opaca observations may be misidentified I. cornuta (Chinese) or I. aquifolium (European). I can suggest corrections now that I know what I’m doing.

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