Which plant is known for estrogenic effects on reproduction?

• A. Lupin
• B. Subterranean clover
• C. Buckwheat
• D. St. Johnswort

Answer: (B)

Estrogenic effects in plants come from phytoestrogens—plant compounds that can bind estrogen receptors and alter reproductive signaling. Subterranean clover is a classic source of these compounds in grazing systems; it contains phytoestrogens that mimic natural estrogen. When animals like sheep eat significant amounts, these compounds interfere with normal reproductive hormones, leading to issues such as irregular estrous cycles, reduced fertility, or even abortion. This association with clover-producing reproductive disruption is well documented, making the plant strongly linked to estrogenic effects on reproduction. The other plants listed are not as widely recognized for causing reproductive estrogen mimicry; they may have other toxic or medicinal properties, but their reproductive estrogen effects are not the defining feature like those seen with subterranean clover.