The 'Japan' could be
B. innominata, but that's only a guess (with the possible execption of
B. monnieri, there are no
Bacopa there). If the corolla is white, that could be telling. I collected some of that species to cultivate and compare, but unfortunately, it melted.
Thanks for making the specimens. Getting fruit for them really helps.
I wonder if the 'Colorata' is really
B. caroliniana. Could be. Again, it shouldn't be that hard to ID. The
Hygrophila though...a tough one. Very tough.