'Cassia fistula', commonly known as golden shower, purging cassia, Indian laburnum, is a flowering plant in the subfamily, 'Caesalpinioideae of the legume family, 'Fabaceae'. The species is native to the Indian subcontinent and adjacent regions of Southeast Asia. It ranges from eastward throughout India to Myanmar and Thailand and south to Sri Lanka and southern Pakistan. It is a popular ornamental plant and is also used in herbal medicine.

The golden shower tree is a medium-sized tree, growing to 10–20 m (33–66 ft) tall with fast growth. The leaves are deciduous, 15–60 cm (6–24 in) long, and pinnate with three to eight pairs of leaflets, each leaflet 7–21 cm (3–8 in) long and 4–9 cm (1.6–3.5 in) broad. The flowers are produced in pendulous racemes 20–40 cm (8–16 in) long, each flower 4–7 cm (1.6–2.8 in) diameter with five yellow petals of equal size and shape. The fruit is a legume, 30–60 cm (12–24 in) long and 1.5–2.5 cm (0.6–1.0 in) broad, with a pungent odor and containing several seeds. The tree has strong and very durable wood.

The golden shower tree is the state flower of Kerala. The flowers are of ritual importance in the Vishu festival of Kerala, and the tree was depicted on a 20-rupee stamp. The golden rain tree is the national flower of Thailand; its yellow flowers symbolize Thai royalty and the blossoms commonly referred to as dok khun.

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