plant morphs under high light/CO2

Howdy,

I've noticed some plants look rather different after growing out in my
plant tank from how they looked in the LFS at purchase. On the other
hand, some plants appear not to change significantly their morphology.

Cases in point:
Anacharis - bought at LFS with deep, deep almost forest-green
color, leaf whorls spaced very closely along the stem, leaves kinda
short and broad. After adjusting to my tank, it now grows like mad,
but the leaves are a lighter green, MUCH longer (2-3x longer maybe) and
thinner, and leaf whorls are spaced much much further apart on the
stem.
Amazon sword: bought at LFS with deep, deep green color, and the
leaf/stem shape resembled a big wooden spoon. Long stem, and oval leaf
at the end. In my tank, the color is a lighter green, the leaves are
of longer total length, and the leaf has little stem and is rather
shaped like a long dagger. Also, new leaves seem to have a
rust-colored vein structure for a few days before greening.

BUT...
Ludwigia repens: gets a little redder but same morphology.
Bacopa monnieri: identical to time of purchase, just rootier.
Cabomba caroliniana: identical to purchase.
Rotala indica: identical to purchase.

SO...

The question is, are these effects common? I assume it's nothing to
worry about, but it's interesting and obvious enough that you've all
probably seen it. What say?

--
Trapper, in snowy NYC