Clock flower (scientific name: Turnera ulmifolia L.) is a plant of the genus Turnera ulmifolia. Perennial herb or subshrub, 30-80 cm tall. The leaves are alternate, elliptic to broadly lanceolate, with serrated edges, and a pair of obvious glands at the leaf base. The flowers bloom in the leaf axils at the end of the branches, and the corolla is golden yellow with 5 petals. Capsule, dehiscent or not; seeds few to many. Flowering in spring and summer.
Native to tropical America. It grows on roadsides, grass slopes or jungles at an altitude of 120-800 meters. It likes light and is suitable for growing in warm and humid climates.
Clock flower can be used as a potted plant for ornamental display, and can also be used for flower beds and flower mirrors in parks and courtyards. It is an excellent garden ornamental flower; the root or the whole plant can be used as medicine, with a bitter taste and slightly cold nature; it is slightly poisonous; it has heat-clearing properties Detoxification, deworming and other effects. It is used by Brazilian folks for anti-inflammation, mainly to treat influenza and abdominal pain caused by insects.