This taxon was described originally by Schumann as having two calyx lobes. Although usually two calyx lobes are present, sometimes three or four are also encountered, the fourth one often aborted or only 0.5 mm long, while the third is usually as long as the other two or about 2-3 mm long.
Diodia kuntzei occurs in or near water. The Venezuelan record is a northwestern extension of range for the species, which is otherwise known only much farther south. It is related to the Cuban D. simplex Sw., which has smaller corollas and broader leaves often ciliolate on the basal margins. It is also closely related to D. virginiana L., which has two calyx lobes and glabrous leaves.