It's not Cyperus longus Myriam, I have that and Carex pseudocyperus, my original plant of the Carex has struggled in the place I have it in bog soil at the side of the drain, but it keeps setting plants here and there elsewhere.
The flowers don't match Carex pseudocyperus but the leaves do look like a Carex. Sedges have edges, do the leaves feel sharp on the edges?
