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
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.