thats quite interesting. I dont really know for sure, but the stuff I have is very tight spirals, only grows to about 15cm max. Was doing well in my 35g with hagen yeast and 2wpg.... lots of runners, and never needed trimming of course coz its so small. Was sold to me as twisted vallis, but since saw it on the web identified as vallis. torta.Error said:Only three (four) valid species of Val are really in culture. V. americana, V. spiralis (which is not always spiral), V. nana (V. gracilis) and rarely V. caulescens.
The "Torta" stuff I think is V. americana var. biwaensis.
Really, to be sure (if you want to ID it), get it to flower. A good guide for differentation is on page 436 in Kasselmann.
I speak only from my experiences with the Val I have kept. Every time I gave one a "hair cut", the leaves grew for a few more days, possibly a week or more, but eventually browned and died. The untrimmed leaves, however, last for months.little worm on a big hook said:i dont know about the leaves turning brown if they are cut because this hasnt been my experience. The cut leaves continue to grow and must be cut again and again. i have been cutting them since ive gotten them about 7 months ago and have not had any problems so far. this seems to be common practice among other aquarists also, and would not be endorsed by so many if it caused the plants death.