Calotropis procera is a large, erect shrub growing 4 metres or more tall. The plant can sometimes produce a single bole that is free of branches for up to the first 2.5 metres.
The tree has a wide range of medicinal uses and is the source of various materials, especially fibre. It has been cultivated in South America and on the Caribbean Islands for the production of fibres. It is well suited for intensive energy farming in arid or semi-arid regions where frost is not a limiting factor. It is cultivated as a medicinal plant in China.

Known Hazards

The juice of the plant is poisonous - it has been used as an infanticide in Africa. Both the bark and the latex are widely used as arrow and spear poisons. The latex is cardiotoxic with the active ingredient being calotropin.

Habitat

A weed along degraded roadsides, lagoon edges and in overgrazed native pastures. It has a preference for and is often dominant in areas of abandoned cultivation, especially in sandy soils in areas of low rainfall.

Cultivation Status

Cultivated, Wild

Cultivation Details

A plant of the semi-arid tropics and subtropics, it is found growing at elevations from sea level to 1,300 metres. It grows best in areas where the mean annual rainfall is in the range 300 - 400mm. Requires a sunny position. Prefers disturbed sandy soils. Established plants are very drought-resistant and are salt-tolerant to a relatively high degree. It has a preference for and is often dominant in areas of abandoned cultivation especially sandy soils in areas of low rainfall. When growing in sandy soils, this species has been known to escape from cultivation. The plant has spread widely from its original range and has become naturalized in many areas of the tropics and subtropics. Through its wind and animal dispersed seeds, it quickly becomes established as a weed along degraded roadsides, lagoon edges and in overgrazed native pastures.
When cultivated, annual yields of up to 500 kg/ha of fibre are expected. A single harvest per season is preferable to a double (or triple) harvest; a single harvest would result in a net saving of energy input both on the farm and in the processing plant. The plant is often an indicator of overgrazed land.

Edible Uses

The leaves have been used as a soup ingredient in sauces. A rather strange report - see the notes above on toxicity.

Medicinal

Compounds derived from the plant have been found to have emetic-cathartic and digitalic properties. The principal active compounds are asclepin and mudarin. Other compounds have been found to have bactericidal and vermicidal properties. The root bark is an emetic. An infusion of bark powder is used in the treatment and cure of leprosy and elephantiasis. It is inadvisable to use bark that has been kept for more than a year. The extremely poisonous roots are used in the treatment of snakebites.
The leaves are used for the treatment of asthma. The milky sap is used as a rubefacient and is also strongly purgative and caustic. The latex is used for treating ringworm, guinea worm blisters, scorpion stings, venereal sores and ophthalmic disorders. it is also used as a laxative. Its use in India in the treatment of skin diseases has caused severe bullous dermatitis leading sometimes to hypertrophic scars. The local effect of the latex on the conjunctiva is congestion, epiphora and local anaesthesia. The latex contains a proteolytic enzyme called caloptropaine. The flower is digestive and tonic. It is used in the treatment of asthma and catarrh. The twigs are applied for the preparation of diuretics, stomach tonic and anti-diarrhoetics and for asthma. Also used in abortion, as an anthelmintic, for colic, cough, whooping cough, dysentery, headache, lice treatment, jaundice, sore gums and mouth, toothache, sterility, swellings and ulcers.

Agroforestry Uses

A source of green manure. The plant can help improve soil water conditions and also acts as a soil binder. Plants often escape from cultivation, especially when growing on sandy soils. It often self-sows freely on overgrazed land and has been used as an indicator of exhausted soil.

Other Uses

A strong fibre is obtained from the stem. Durable under water. White, silky, strong, cylindrical, flexible and durable stem fibre used for various purposes, such as for making ropes, to form cheap cots, gunny bags, bow strings, fishing nets, and in the manufacture of paper, pulp and duplicating stencils. Strong inner bark fibres produce a binding material and are processed into fabrics. The floss from the seed capsules is used as a stuffing material in mattresses etc. The floss from the seeds, which is about 2 - 3.5 cm long, white silky and strong, is used as an inferior stuffing for mattresses and pillows as well as for weaving into a strong cloth. The floss may also substitute cotton wool for surgical purposes. The plant is the source of a rubber-like product called Mudar Gummi. The liquid latex can be used as a renewable source of hydrocarbons and intermediate energy resources. The latex contains 11 - 23% of rubber. The latex is 80% effective in inhibiting the activity of the tobacco mosaic virus. The leafy branches are said to deter ants. In a trial, a methane extract of the leaf at a concentration of 10,000ppm in distilled water reduced the egg hatching of root nematodes by 97% after 21 days compared with a control. A macerated bark extract can be used for dyes. An ideal plant for monitoring sulphur dioxide emissions in the air.
The stems are termite proof and are used for roofing and building huts. The very light wood can also be used for fishing net floats. The wood is a source of charcoal, used for making gunpowder. Stems produce a good charcoal, while the stem pith makes good tinder.

Propagation

Seed. The tree seeds freely, and natural regeneration is common. Vegetative propagation through half stumps assumes a special importance as compared with the entire stumps because they help in faster multiplication of the parent genotype with plus characters, as each plant gives rise to 2 half stumps. Stumps also help in propagating only 1 plant. Vegetative propagation through stem and root cuttings is very useful in large-scale multiplication of the superior genotypes.