Well...really fast but I have really good lighting :) aaaaand...water conditions...I have well water so its really hard but very acidic. Also my temp runs between 76-81F (depending on which tank not in a single tank) and the plants do fine! They will grow slowly if your lighting is not good enough. I would invest in fluorescent bulbs (2 WPG or you're gonna get alage problems) and they need to be in the 6700-10000K range.
Flowers! I'm jealous!! My cabomba is going to flower...maybe (it might not flower, I'm not sure if it does but it looks like it!)... :) I swear, I love my plants* almost* as much as my fish, teehee! Vallisneria should do well in lower light, too. That's a good choice and its cheap!
I would bet money that if it smells strongly like eucalyptus (it just smelled like Vicks Vapor Rub to me) that it IS bacopa! I love my bacopa...its a lovely fast growing plant, which needs moderate to high light. I have not supplemented mine with CO2 or Fertilizers (yet) and its grown quite a bit! Chances are if its doing well at your LPS, it'll do well in your tank, provided you give it enough light! I also love that it is scented...a little water herb! :))