Which of Charles Darwin's sons became a prominent botanist?

Francis Darwin was the son of Charles Darwin who became a prominent botanist.

Born in 1848, Francis was Charles Darwin’s third son and seventh child with Emma Darwin. Although he initially studied mathematics at Cambridge and later trained in medicine, he never practiced as a doctor. His scientific career centered on plant physiology and botany.

Francis worked closely with his father on experiments concerning plant movements, especially phototropism—the tendency of plants to grow toward light. Their research on grass seedlings helped show that the tip of a young shoot detects light and influences growth. Together they published The Power of Movement in Plants in 1880.

The other choices represent different scientific or professional paths. George Darwin became an astronomer and mathematician, while Horace Darwin was an engineer and civic figure. Leonard Darwin later became an army officer, politician, and eugenicist. Francis also edited several collections of his father’s letters and autobiography, helping preserve Charles Darwin’s scientific legacy.