ID needed on a couple of flowers

I found these growing in a ditch near my house, can anyone ID them. This flower is about an 1 1/2 inches.

Here is the plant.

Next flower

Here is a shot against my hand for scale.

Here is the stalks.

The first one is Ludwigia octovalvis, Narrow leaf Water Primrose
http://www.wildflower.org/plants/result.php?id_plant=LUOC
The second one I have to check around.
Josephine.

I think the other one is a Dotted Smartweed, but not sure
http://wildflower.org/plants/result.php?id_plant=POPU5