Stewart Robert Hinsley writes
In message , Pam Moore
writes

The second I think is what I call starweed, which becomes a menace
when it gets established on top of pots.
Can't give botanical names.

Did you mean the 3rd, which Des suspects of being a water-starwort?
Unfortunately the predominant meanings of starweed - if one believes
Google - are Stellaria media (chickweed) and Plantago triandra (a New
Zealand plantain).

It doesn't look like the star-wort that we have in the ponds at the
nature reserve - that looks much more cross-like in pattern and is
nearer the surface. Colour is right, though.

Could the other one possibly be greater spearwort? - see, for example
http://www.map-reading.co.uk/wildflo...les/sl7117.htm
--
Kay