About Kerria japonica (L.) DC.
Kerria japonica (L.) DC. is a shrub that grows 1–3 meters (3–10 feet) tall, with weak arching stems that often scramble over other vegetation or rocks. In the wild, this species grows in thickets on mountain slopes. Its leaves are alternate, simple, and 3–10 centimeters (1–4 inches) long, with a doubly serrated margin. It produces golden yellow five-petaled flowers, spaced evenly along branches of new green growth. The fruit is a dry single-seeded achene that measures 4–4.5 millimeters (0.16–0.18 inches) long. In garden cultivation, Kerria is valued for its bright golden yellow spring flowers. It grows best with partial shade rather than full sunlight, to prevent the flowers from blanching. It requires pruning after flowering to maintain good health and vigour. Two cultivars of Kerria japonica have earned the Royal Horticultural Society's Award of Garden Merit: 'Golden guinea' and the double-flowered 'Pleniflora', which is commonly called bachelor's buttons. This plant has anti-inflammatory properties. In China, a decoction of its flowering shoots prepared with honey has been used to treat coughs and gynecological disorders.
