Pruning/Propagation Question

Looks like a Water Wisteria (Hygrophila difformis). Maybe two, bottom leaves look like when it grows emerged. Upper leaves look like when it grows submerged.

Haven't had much experience propagating them yet, but they seem pretty easy. The ones I got were in those Petco plastic tubes so I had to cut off the bottom half of the stem (had started rotting). Took a few leaves off the lower area to make a stem long enough to bury. Stuck 'em in the substrate (sand) and new roots popped right out in a couple days and they started growing. Still too small to really do much (though I do see the leaf change starting that yours seems to have).

Stem plants seem to propagate very easily as long as they have enough stem to grow roots and leaves. I have a Ludwigia that was basically a snapped off branch with a few leaves. Stuck it in the sand and it rooted in days (slow growing so far since the loaches LOVE uprooting it). Hell I've got some Water Sprite that was basically left over remains from a heavily rotted plant. Threw them in a snail tank over a month ago as 'food' thinking they'd rotted away. Moved them to a tank with light a couple weeks ago when I took apart the snail tank and saw they hadn't rotted away (turned completely brown but kept the shape). I now have tiny leaves popping out of the brown remains. Pretty hardy things. Seems like half the time all they need is leaves and somethings for roots to grow out of and they propagate.

It is a whisteria, They propagate on their own. Over time small leaflets start to separate from the plant, and tiny roots become visable, none of which are in the following pics.

I have leaves of wisteria that have either been trimmed or broken off and if I leave them in the tank they will grow just floating.
I've always just pruned them down to whatever size I want them to be, plant the rest if I want to keep it, but usually just toss out the extra or find someone to send it to.

I just try to trim them to where I have a bit of stalk to plant them into the substrate with because I don't like for them to float.

i just cut stems off as needed and replant them, or leave them floating, doesn't seem to matter too much. I prefer to plant them though because they are pretty bushy and block the light if left floating.

I've found that it reproduces all on it's own. You'll see long roots form and, not long after, that piece will be floating. I just shove it into the gravel and it grows quite well. Some of the old leaves rot away, but the new plantlets keep on truckin'!

That said, if it's getting too tall or too bushy for you, simply snip what you don't want off and plant it elsewhere. It's actually one of my favourite plants thus far...easy to grow, great cover for fry, great to hide heaters and such.

To jump in on this thread....I have the same plant in my tank. They have been there a while, including the Green Water War of 2010, which we finally won. All the plants are doing great now, but the H. difformis had almost no growth during GWW 2010, but now it is going gang busters. The problem is the bottom 8 inches of the plant is all stem, the top 2 inches is tons of leaves. Suggestions? I was thinking of chopping most of the stem off and replanting the top healthy part.