Valliseneria "strings"

     I just discovered three extremely long "strings" (up to 28" long) that 
     have grown up out of the center of my very large Valliseneria asiatica 
     (spiral val) and are draped across the surface of the water. They are 
     pale green strings that have a thickened tip which looks like it could 
     be a bud.  Is this the way vallesineria flower?
     None of the buds have opened and I wondered if I needed to help them 
     break contact with the water in order to encourage them to flower.
     I've had valliseneria before, but never saw this phenomenon.
     Also, how large can I expect to get my echonidorus parviflorus (black 
     amazon swords) to grow?  They are small, 12-leaved, and about 3" tall. 
      I was hoping they'd grow to 8-9".  Any help out there?