Bacopa flowering submerged

My wife noticed the darnest thing last night; one of the Bacopa
stems has opened up a small blue flower COMPLETELY SUBMERGED.
This is the first time we've seen aquatic flowers underwater.
Let me explain how I think it happened; some of the Bacopa stems
have been growing quite vigorously and the stalks are sturdy
enough that one or two have emerged several inches above the
surface of the water. I left it that way for a while as a curiosity
and to see how the emersed leaves would look. (similar the the
submersed leaves, just smaller with a slightly waxy appearance)
Later I cut these long stems in half and replanted the tops.
This appears to be one of the replanted emergent stems that had
already begun the process of developing a flower bud.

The flower stem is about 1.5 cm in length and the size of the
flower is about one cm. The flower petals are fairly large for
an aquatic flower and have a purplish blue colour. I don't
think it is going to last very long under the water. I guess
I should have let it stay emergent for a while longer. :-}

Has anyone played around with Bacopa flowers and seeds to try
propagating this way? Do you need flowers from a plant not
derived from the same genetic mother by vegetative propagation
in order to produce fertile seeds? I think all my specimens
came from the same original bunch of Bacopa a long time ago
which were also likely all from the same biological mother.