Three-seeded Mercury

Acalypha rhomboidea

 From Missouri Plants

Flowers - The staminate flower is covered with yellow pollen, while the pistillate flower produces a 3-lobed spheroid fruit that is typical of the spurges. Each fruit contains three seeds.
  Flowering - July - October.

Habitat - Open woods, moist soils, gravel bars, waste ground, roadsides, railroads.

Origin - Native to U.S.

Other info. - The plant is a member of the Euphorbiaceae but unlike many members of that family, it has clear sap. The typical plants from this family have milky white sap.