I found this excellent image uploaded by Saroj ji in Flicker.
Here the male calyx segments are 6-lobed and each lobe is again bilobulate. This character distinguishes this species from Breynia quadrangularis which is always having six triangular -lanceolate lobes of male calyx.
Airy Shaw (1972) and Van Welzen (2003) considered and treated both of these species as conspecific but B. quadrangularis is in my opinion is distinct on this character as the characters of the male calyx are of great diagnostic impotence in Breynia.
Regards.
Tapas.