I found this plant near a drainage by my school. I doubt it's aquatic but still worth a try.
(1) The species of Ludwigia found in CA are: palustris, peploides ssp. peploides, peploides ssp. montedivensis, repens, and uruguayensis. It looks most like either L. palustris or more likely uruguayensis to me.tsunami said:Plant1 is definitely a species of Ludwigia.
Plant4 looks a lot like a Rotala. Could it be Rotala ramoisir (check spelling)? It's one of the few Rotalas native to the U.S.
Plant5 reminds me of a Polygonum.
The last one really doesn't look aquatic.
North American Ludwigias are excessively difficult to identify without the flower. At first glance it looks like L. peploides ssp. montedivensis, but I have a few questions. Where did you find this, i.e. state, county, river, etc.? Also, are the stems and leaves pubescent at all, or are they glabrous? When (if at all) it flowers, does the flower rise up from one of the nodes on a separate stalk or does it develop directly from the rosette? If you have seen the flower, how many petals does it have, also how many stamens?spituch said:Error,
If you are a Ludwigia fan please look at this plant (Unidentified #1):