Yellow jessamine is a climbing vine that produces funnel-shaped yellow flowers. It also can be called Carolina jessamine or evening trumpetflower. Yellow jessamine is the state flower of South Carolina. Its leaves are shiny and sword-shaped. The fragrant flowers grow in clusters. The flowers, leaves, and roots are poisonous. The roots produce gelsemium, a traditional medicine used to treat malaria, neuralgia, and rheumatism.