Lucas Land
Ladies Thumb
Polygonum persicaria
from the link ☼
branched annual with stems growing erect or spreading from 0.2 to 1 metre long; lance-shaped leaves with black blotch in centre and a thin papery sheath with long hairs at the base; flowers are pink in a small spike-like cluster
green smartweed (Polygonum scabrum) is similar but with green flowers and glandular dots on the undersurface of upper leaves
Like most of the smartweeds when chewed, the flowers have a peppery taste.