# L. palustrus vs. L. repens



## mudboots (Jun 24, 2009)

I went to a wetland site that was inundated to about an inch on average across a couple of acres (some isolated deeper areas). I found 5 sps of _Ludwigia_. I have to revisit the site in August and hope to get pics of a species thought to be _L. pilosa_. But I brought one home and had a tough time differentiating between _L. repens_ and _L. palustrus_. The key I was using at the office (North Central Texas - Diggs, Lipscomb and O'Kennon) differentiated mostly based on the repro structure, noting that in _L. repens_ it sits on a pedicel that can be as short as 0.3mm, while the structure in _L. palustrus_ is sessile.

So, I am leaning toward _L. palustrus_, but wanted some help confirming. Here are the pics of the specimen I brought home. It was prostrate, making a mat in the field, but has straightened since I planted it in the picotope yesterday. You can see the petioles, but it fits in the range described for both species, as does the leaf shape...I did not cut open the capsules.


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## Michael (Jul 20, 2010)

_Shinner and Mahler's Illustrated Flora of North Central Texas_--I know it well! Can't help with the_ Ludwigia _though, those things confuse me to death.


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## Cavan Allen (Jul 22, 2004)

It looks like_ L. palustris_ to me. _L repens_ capsules are not as stout and have shorter sepals. The latter also has petals, though they are shed somewhat early. Also, I've just plain seen a lot of both.  Could be a hybrid of the two, though I still lean to palustris.

This is available online free somewhere, though I have to dig it up. It is by far the best reference for this:
http://www.google.com/url?sa=t&rct=..._f2lCg&usg=AFQjCNEKU2zFZvYlwto5ryIVeFqJdOY_cw


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## mudboots (Jun 24, 2009)

Awesome and Thanks!!! I wish L. decurrens would grow submersed in aquaria...it's one of the nicer ones I saw out there. Maybe there's room for a stem or two in the Wetland-n-a-Box at my office.


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## Cavan Allen (Jul 22, 2004)

Found it!

http://www.biodiversitylibrary.org/pdf3/003678100087371.pdf


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## mudboots (Jun 24, 2009)

Thanks Cavan; I'll swim through it when I get back from my wetland training travels.


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