The diadelphous stamens arrangement is exemplified by which plant group?

• A. Solanaceae
• B. Cucurbitaceae
• C. Papilionaceae
• D. Brassicaceae

Answer: (C)

Diadelphous stamens describe a pattern where the stamens are organized into two distinct groups. This arrangement is a hallmark of the legume family, specifically the Papilionaceae. In these flowers, nine stamens are fused by their filaments to form a single tube that surrounds the pistil, while the tenth stamen remains free. This two-bundle setup gives the characteristic papilionaceous flower form, with its banner, wings, and keel, and it helps position pollen for transfer by pollinators. Other plant groups show different stamen patterns—some have all stamens free and unfused, others have different fusion patterns such as a single fused group—so the diadelphous configuration is distinctive to this legume group.