The pale pink flowers and fluffy white leaves of marsh mallow are along the path edge between the west hide and sluice to the end of August.
From the independent.co.uk
Arrowhead root with an edible tuber is common here, as are maples, lizard's tail bushes with white bottlebrush-like flowers, also swamp mallow and its cousin marsh mallow.
From the stltoday.com
Today in the park, we find mallow, with its seeds, and salsify, a starchy root that looks like a white carrot.