The first stage of a bullrush is a seed. The seed is very small I imagine. The second stage is a sausage-like plant. The third stage is when the sausage part turns a bit furry in the autumn/winter. The final stage is when the furry part dissolves. I hope you enjoyed this explanation :-)
Every month this year we've taken a
photo of the bullrush plants near our house, to see how they change.
Tomorrow I'll share the photos.