Diadelphy can be found in
Pisum
Citrus
Bombax
Brassica
A.
Pisum
Diadelphous flower stamen is united by their filaments so as to form two groups. In Pisum, stamens are fused in two sets.
In Citrus, polyadelphous condition is found. It is a condition when stamen is united by the anthers into three or more groups.