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.