Giant Milkweed, Crown Flower, Giant Calotrope, Swallow-wort
Calotropis gigantea

Family: Apocynaceae

What it is like

Native to parts of Southeast Asia, India, China, Sri Lanka, Pakistan, and Nepal, Crown Flower or Calotropis gigantean is a fast-growing, large shrub that reaches up to 4 m tall with clusters of white or lavender waxy flowers. The leaves are light green and oval. Crown flower produces a durable fiber known as 'Bowstring of India' used in making ropes and carpets among others. The plant reportedly has antifungal and insecticidal properties. In traditional medicine, crown flower is used as treatment for common diseases such as fever, coughs and colds, eczema, rheumatism, nausea, and diarrhoea. It yields poisonous latex that is used in poisoning arrows. The latex is also used for treatment for sprains, boils, body pains, and pimples. The bark is used for neurodermatitis and syphilis. Mature seed pods are sources of floss that have a wide range of uses. The wood is used as fuel and made into charcoal. Note. Sometimes misspelt as: Calotropis giganteus

Calotropis gigantea is an evergreen Tree growing to 5 m (16ft) by 6 m (19ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 10 and is frost tender. The flowers are pollinated by Bees, Butterflies, Wasps. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in saline soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Height (m): 5

Where it is found

Dry coastal areas, along the sheltered shores of lagoons, overgrazed pasture land. Woods of dry areas, stream banks from sea level to 1,400 metres in southern China.

E. Asia - southern China, Indian subcontinent, Myanmar, Thailand, Laos, Vietnam, Malaysia, Indonesia

Conservation Status: This taxon has not yet been assessed.

Countries/locations it is found in

Found In: Africa, Angola, Asia, Burma, Central Africa, Central America, China, East Africa, East Timor, Guyana, Hawaii, India, Indonesia, Kenya, Laos, Malaysia, Maldives, Mauritius, Mozambique, Myanmar, Nepal, Pacific, Pakistan, Papua New Guinea, Philippines, Samoa, SE Asia, Seychelles, South America, Sri Lanka, Sudan, Suriname, Tanzania, Thailand, Timor-Leste, Trinidad-Tobago, USA, Venezuela, Vietnam, West Indies.

How it is used

Food

Rating: 2

The central part of the flower is candied and used as a sweetmeat. An alcoholic drink is made from the leaves. The plant yields a manna.

Manna: this is a sweet substance that exudes naturally from certain plants, usually from the stems.

Drink: not including plant saps, tea or coffee substitutes.

Medicine

Rating: 3

The milky sap (latex) coagulates when warm and is said to have similar cardiac properties to digitalis (from various Digitalis spp.). It is also considered to be antiseptic, emetic, purgative and vermifuge. It is used in the treatment of a variety of other conditions including dysentery, leprosy, elephantiasis, epilepsy, asthma and many other complaints. Mixed with salt, it is taken orally as an emetic for treating severe colds. In Nepal, the latex is applied to sprains, body pains, boils and pimples. The milky latex is used externally to stop bleeding, and for treating a wide range of conditions including leprosy, rheumatism, ringworm, boils, scabies, stings, burns, bruises, cuts, sores and wounds, . It is applied to the gums and teeth to treat caries and toothaches. The bark is used as a medicine for the treatment of neurodermatitis and syphilis. The powdered bark is used to treat diarrhoea, dysentery, elephantiasis, and leprosy . The stem bark is diaphoretic and expectorant, and is used for dysentery, spleen complaints, convulsions, lumbago, scabies, ringworm, pneumonia, and to induce labour. An infusion of the leaves is used to treat severe chest colds and heart conditions. The leaf juice is used in the treatment of intermittent fever. The smoke of dried, burned leaves is inhaled to calm asthma attacks. The crushed leaves are warmed and used as a poultice on sores, burns, headaches and rheumatic pains. The powdered flowers are valued for treating coughs, colds and asthma. An infusion is taken to treat intestinal worms, rheumatism and epileptic attacks. The juice of young buds is dropped into the ear in the treatment of earache. The fruit pulp is considered abortive.

Abortifacient: Causes an abortion.

Antiasthmatic: Treats asthma.

Antidiarrhoeal: Provides symptomatic relief for diarrhoea. Also see Astringent.

Antirheumatic: Treats rheumatism.

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Diaphoretic: Induces perspiration.

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Emetic: Induces vomiting.

Epilepsy: Used in the treatment of Epilepsy - a disorder in which nerve cell activity in the brain is disturbed, causing seizures.

Expectorant: Clears phlegm from the chest by inducing coughing.

Febrifuge: Reduces fevers.

Leprosy: Used to treat leprosy - a chronic bacterial infection of the skin and superficial nerves (in the skin) caused by Mycobacterium leprae.

Mouthwash: Treats problems such as mouth ulcers.

Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.

Purgative: A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.

Skin: Plants used in miscellaneous treatments for the skin.

Stings: Used in the treatment of stings and insect bites.

Vermifuge: Expels and kills internal parasites.

Other

Rating: 4

Other uses rating: High (4/5). Seaside, Specimen, Large Planter, Coastal Screening, Xerophytic. Agroforestry Uses: As it thrives upon soils where nothing else will grow, needing neither culture nor water, it has been considered a good plant for bringing waste land under tillage and for reclaiming drifting sands. The leaves can be used for mulching, green manuring of rice fields and for binding sandy soil. The plant is sometimes grown as a hedge. Other Uses: A fine fibre is obtained from the bark of the stems. Very strong, it is said to possess many of the qualities of flax (Linum usitatissimum), though it is somewhat finer. It is much used for making textiles, fishing nets and bowstrings. The mature seed pods contain a large quantity of floss, which has a variety of uses. For example, it can be used to stuff pillows etc or mixed with other fibres to make cloth. It is a Kapok substitute, being very water repellent it can be used as a buoyancy aid in Life Jackets or as a stuffing material. The floss absorbs oil whilst repelling water and so has also been used to mop up oil spills at sea. Candlewicks can be made from the seed floss. The twigs are used as chewsticks for cleaning the teeth. The juice is used in making a yellow dye and in tanning. The wood is sometimes used for fuel, but it is of poor quality. However, a good quality charcoal is obtained from the wood and can be used for making gunpowder. Attractive flowers are long lasting and used for floral arrangements. May exhibit mosquito controlling properties against Culex gelidus and Culex tritaeniorhynchus mosquitoes which serves as vectors for Japanese encephalitis. Host to a variety of insects and butterflies including Hawaii's non-migratory monarch butterflies. Carbon Farming - Industrial Crop: hydrocarbon, fiber. The dogbane-milkweed family Asclepias, Apocynum, Calotropis, and Trachomitum spp) has been used for fiber industrial crops for millennia with a number in cultivation as regional crops. All of these crops are dual-purpose fibres, offering bast fibres from the stem and seed fiber or ‘floss’ in the fruit pods. Many have also been identified as potential hydrocarbon crops due to high latex content. Could be integrated into various agroforestry systems rather than as monocultures.

Bedding: Used as a lining for sleeping on or putting fruits etc on.

Charcoal: Used for fuel, drawing, deodorant, filter, fertilizer etc.

Cut flowers: Cut flowers are flowers or flower buds (often with some stem and leaf) for decorative use.

Dye: Plants that provide dyes.

Fibre: Used for making cloth, rope, paper etc.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Green manure: Fast-growing plants that can be used to increase the fertility of the soil.

Hedge: Plants that can be grown as hedges.

Insecticide: Kills insects.

Mulch: Used for covering the ground to conserve the nutrients in the soil.

Soil reclamation: Plants that can be grown in such circumstances an the spoil tips of mines in order to restore fertility.

Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.

String: Plants that can be used for string or can be easily made into a string. See also Fibre. Plants for ropes may be included.

Stuffing: Used in making soft toys, mattresses, pillows etc.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Teeth: Plants used to clean and care for the teeth.

Waterproofing: Does what it says. See also Pitch and Oil.

Wick: Used as a wick for candles, lamps etc.

Industrial Crop: Fiber: Clothing, rugs, sheets, blankets etc. Currently, almost none of our fiber are produced from perennial crops but could be!

Industrial Crop: Hydrocarbon: Materials, chemicals and energy include bioplastics, rubber, biomass products gasoline, jet fuel, diesel, butane, propane, biogas. Plants are usually resprouting plants and saps.

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Regional Crop: These crops have been domesticated and cultivated regionally but have not been adopted elsewhere and are typically not traded globally, Examples in this broad category include perennial cottons and many nuts and staple fruits.

Industrial Crop: Fiber: Clothing, rugs, sheets, blankets etc. Currently, almost none of our fiber are produced from perennial crops but could be!

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Management: Standard: Plants grow to their standard height. Harvest fruit, seeds, or other products. Non-Destructive management systems.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

Coppice: A traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Hedge: Hedge

How it is grown

Succeeds in the drier tropics. Most commonly found in areas of the tropics with a specific dry season, at elevations up to 1,000 metres. An excellent plant for the seaside garden. Prefers a well-drained soil in a sunny position. Succeeds in a variety of soils, but prefers littoral, sandy soils. Plants can thrive in dry sands. Established plants are very drought tolerant. Plants are tolerant of salt-laden winds. One hectare of ground stocked with plants 30cm apart can yield 24 tonnes of green stems, from which 260 - 350 kilos of fibre can be obtained. The plant is of great religious significance in India, where it is sacred to the God Shiva. Plants can flower all year round, but the main flowering is in the hot season. Carbon Farming - Climate: tropical. Humidity: arid to humid. Cultivation: regional crop. Management: standard, coppice.

Propagating it: Seeds, Cuttings. Layering. Seed Collecting: Allow pods to dry on plant; break open to collect seeds. Some suggestions that gloves should be worn to protect hands when handling seeds.

Best place to grow:

Habit: Tree

Hardiness: 10-12

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: No shade

Moisture: Dry, moist

Things to keep in mind

The sap (latex) is somewhat poisonous. It is used for poisoning arrows. All parts of the plant are toxic, due to the presence of several cardiac glycosides. The plant is also known to cause allergic contact dermatitis, and the latex causes kerato-conjunctivitis.(Parts of plant are poisonous if ingested)

Its other names

Local names

Crown Flower or Calotropis gigantean. Other Names: Biduri, Indian milkweed, Kapal kapal, Kayu berduri, Kemengu, Lechoso, Pua kalaunu, Rak-dok, Rembaga, Remiga, Widuri. Bow-string hemp, Crown-flower. Akon.

Synonyms

Asclepias gigantea L. Periploca cochinchinensis Lour. Streptocaulon cochinchinense (Lour.) G.Don

Giant Milkweed, Crown Flower, Giant Calotrope, Swallow-wort Calotropis gigantea