Cassia fistula



Cassia fistula

L. 1753

pronounced: KASS-ee-uh FIST-yoo-luh

(Fabaceae — the pea family)

subfamily: Caesalpinioideae - the cassia subfamily


common names: cascara, golden shower, Indian laburnum

Cassia (or casia) is the Roman name of a tree with aromatic bark, perhaps the wild cinnamon; fistula, also Latin, means a pipe or tube, obviously referring to the seed pod.

This tree is known locally as Cascara, but the Cascara sagrada long used as a laxative is obtained not from this tree, but from Rhamnus purshiana, a member of the Rhamnaceae or Red Ash family.

This is one of the most brilliantly coloured and spectacular trees seen on Magnetic Island, and indeed in all the tropics, being found in large numbers on roadside verges and in gardens, growing to about 9 metres high. Visitors from overseas often remark on its similar appearance to the Laburnum of northern Europe, Laburnum anagyroides.

A native of India, Cassia fistula has large compound leaves and about 16 pairs of leaflets per leaf. It is semi-deciduous, losing many of its leaves as the first blossoms appear, making them even more prominent. The flowers are large, fragrant, bright yellow, and are borne on long, slender, smooth pedicels. The cylindrical seed pods are at first green, then turn blackish brown as they ripen, and grow to about 30 cm long. They are filled with a viscid, reddish black, sweetish pulp, divided into many cells by hard, transverse divisions. Each cell contains a single glossy reddish brown, oval, rather flattened seed. When the pods are broken open, they give off a strong smell of cascara, the laxative obtained from Cascara sagrada; but beware! Although the tree is used medicinally in many parts of the world, it should be treated with caution. dangerous 2The leaves and bark, although they can be used in tiny quantities, can cause vomiting, abdominal pains and cramp. In tribal medicine in India, the East Indies, Mexico and northern South America, both bark and seeds are used to treat various conditions, including constipation, diarrhoea, malaria, rheumatism, ulcers, epilepsy, worms in the digestive system, diabetes, influenza and tumours, and also for pain relief.

Bees and butterflies love these flowers, so it’s a good tree to plant if you want to attract them. The caterpillars of quite a few Lepidoptera use this as a food plant, including:
       • the Common Migrant Catopsilia pyranthe,
       • the Lemon Migrant Catopsilia pomona,
       • the Small Grass Yellow Eurema smilax and
       • the Pencilled Blue Candalides absimilis.

Its drawback as a garden tree is that it is messy, littering the ground with leaves, flowers, seed pods, and rotten branches that often fall from the tree, which is very susceptible to attack by borers and dry rot, especially when it is stressed by prolonged dry conditions.

This tree yields a hard, strong, durable multipurpose timber. The grainy chocolate-brown to reddish heartwood and contrasting creamy-coloured sapwood makes it an attractive timber for cabinet-making and inlay work. Especially in parts of India and Bangladesh, it is used for making farm implements, including wheels and shafts, for piles and posts, and for constructional purposes. It is also used for charcoal-making. Its hardness makes it very suitable for making mortars and rice-pounders. It is also useful as firewood.


Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.


Photographs taken in Picnic Bay 2005-2013
Page last updated 31st October 2018