Reviewed
Urticaceae (Nettle family)
Broadleaf plant family
This relatively small family of plants has only five genera occurring in Missouri, but one of its members, Laportea canadensis or wood nettle, is a common nuisance plant because of its stinging hairs.
Pellitory
Parietaria pensylvanica
For an idea of relative seed size, each photo contains a millimeter ruler. The distance between increments is 1 mm.