I hardly ever see the flowers on my D. peltata open, but I assumed
that they opened for a short while when I wasn't looking. I got seed
on my plants last year without making any special effort.
I shouldn't worry that the plants are dying back. Hopefully they are
just going dormant. Mine aren't doing this yet, but it no doubt all
depends on conditions. I don't think you can overwater it while it is
growing - mine are stood in water like everything else. I keep them
dry during Summer once they die down, and so far have always repotted
the tubers annually in the Autumn, hoping to time this just before
growth starts. My more mature plants often just produce an upright
stem with no rosette at all. Two of the plants in my crowded pot of
seedlings sown last Summer have produced what I assume should be an
underground stem which would develop a tuber on the end, except these
two aren't underground - they have curled around the surface for an
inch or two - has anyone else seen this?
-- Clarke Brunt (clarke@brunt.demon.co.uk)