蓼 - luxurious grass, a smartweed

water pepper (Persicaria hydropiper f. purpurascens)

water pepper (Persicaria hydropiper)

silver vine (Actinidia polygama); cat powder

kiss-me-over-the-garden-gate (Persicaria orientalis); prince's feather

dyer's knotweed (Persicaria tinctoria, used to produce indigo dye)

water pepper (Persicaria hydropiper)

water pepper (Persicaria hydropiper f. aquaticum)

silver vine (used in traditional Chinese medicine)

dyer's knotweed (Persicaria tinctoria, used to produce indigo dye)

water pepper vinegar; vinegar infused and mixed with water pepper leaves, esp. served with salt-grilled sweetfish

knotweed (Polygonaceae); jointweed; smartweed

some prefer nettles; there's no accounting for taste; every man to his taste