Thanks Aaron and GG. Those were the replies i was looking for.Aaron is right on the money with his answer there. Rotalas, hygros, ludwigias - basically any stem plant that produces side shoots readily can be hacked back. The more easily the plant produces side shoots, the better it will be suited for this type of pruning. .
I am not a stem plant guy , and not a aquascaper per se, so my experience in this arena is somewhat limited. However, one new plant that i have recently fallen in love which does not seem to have the ratty bottom issue is is Rotala verticillaris. It seems to behave different than other Rotala in that it puts out side shoots -- from the substrate-- without top trimming. It also seems to grow at less than half the rate as R. macrandra. In the new Amazonia, the macrandra has required weekly trimming. In my 4-week old substrate, the R.verticillaris has not been trimmed once. I may finally do it next week, but i am still somewhate reluctant because i am really enjoying the new fine leaves that it did not have in my older lower light tank. There, it produced thicker leaves that resembled emersed growth. The new 24" deep tank is under 4 T5 HO Geismanns. The older 16" deep tank with mature sand/peat substrate was illuminated with 4 NO T-12 Triton bulbs. There are many other differences besides lighting and substrate which might explain the verticillaris. In that slower grow tank, the macrandra also grew relative fast and required frequent trimming. On the other hand,
I dont think i topped the R.v in the several months i kept it. When i took the tank down last month, the small number of starting R.v stems had multiplied maybe 10-fold.
Another plant that does not seem to develop many annoying lower stem roots is the asian "pearl grass." One that is among the worst that i have seen is Ludwigia repens.