Staminodes occur in family
The androecium is stamens in the flower which forms a whorl surrounding the gynoecium and is inside the perianth. Stamens can be present as free or fused. The fused stamen can be connate, joined in the same whorl or adnate, joined from more than one whorl. When connate stamens are joined partially into two androecial structures, the condition is termed as diadelphous. Caesalpinioideae has dimorphic or heteromorphic 10 stamen filaments which are arranged in two whorls. There are three long anterior stamens, four lateral medium sized stamens and three posteriors very small which are modified into sterile staminodes. Thus, the correct answer is option C.