Japanese Kerria

Kerria japonica grows to 1–3 m (3–10 ft) tall, with weak arching stems often scrambling over other vegetation or rocks. In the wild it grows in thickets on mountain slopes. The leaves are alternate, simple, 3–10 cm (1–4 in) long, with a doubly serrated margin. The flowers are golden yellow, with five petals, and evenly-spaced along branches of new green growth. The fruit is a dry single-seeded achene 4–4.5 mm (0.16–0.18 in) long.

The plant has anti-inflammatory properties and a decoction of the flowering shoots with honey has been used in China in the treatment of coughs and gynecological disorders.

Kerria is valued in gardens for its golden yellow flowers, which appear in the spring. It is best grown with some shade from full sunlight to avoid blanching the flowers, and needs to be pruned after flowering to maintain health and vigour. Two cultivars have gained the Royal Horticultural Society's Award of Garden Merit, K. japonica 'Golden guinea' and the double-flowered K. japonica 'Pleniflora', commonly known as bachelor's buttons.

Kerria japonica is mentioned frequently in the Man'yōshū, the oldest extant collection of Japanese poetry from the AD first millennium. In addition, the Japanese call the golden yellow color (variously #FFA400, #FFBF00, #F8B500) between orange and yellow yamabuki color (山吹色 yamabuki-iro), from the name of the plant. Qing Dynasty poet Chen Hao (陳淏) celebrated the beauty of Kerria japonica in his agricultural treatise the Flower Mirror (花鏡).