Chloranthaceae

Opposite, toothed leaves with swollen stem nodes on shrubs and herbs; tiny greenish flowers lack any petals or sepals at all, reduced to a single stamen fused directly onto the ovary, clustered into a narrow spike.

The flower here is reduced to its bare functional minimum — a single stamen fused right onto the ovary with no petals or sepals whatsoever — among the simplest floral structures in all flowering plants.

To check whether a plant belongs to Chloranthaceae, compare the leaf arrangement, leaf type, flower symmetry, fruit type, and one distinctive marker together. A single feature can mislead; the family pattern is the combination.