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Crown Flower

Botanical Name: Calotropis gigantean
Family: Asclepiadaceae
Common Name: Crown Flower, Remiga, Merigu, Giant Indian Milkweed, Giant Milkweed, Ivory Plant, Swallow-wort, Asclepiad Tree, Kayu Berduri, Kemengu, Rembaga
Origin: Indian subcontinent, Southern China, Indochina, Malaysia, Indonesia
Leaf Colour: Pale silvery-green
Flower Colour: White or Lavender
Propagation: Seed and stem cuttings
Description: This plant has large, thick, oval, pale silvery-green leaves. The entire plant contains a poisonous milky sap. It can grow to 4 m in height and bears clusters of waxy white or lavender flowers. Each flower has a “crown” containing stamens in the centre of its five petals thus giving it the common name, Crown Flower. The fleshy fruit pods split open when ripe to reveal numerous winged seeds with woolly tufts of hair attached. These woolly hairs help the light-weight seeds to be dispersed by wind.
Part Used: Roots, flowers, bark, plant sap, leaves, seeds, nectar
Used by: People

Fauna – Plain Tiger butterfly, Common Crow butterfly, Carpenter bees, Yellow Aphid, sunbirds
Uses:
As foodSee caution below.

In medicineThe bark is used to treat dermatitis and syphilis. The leaves are used as poultice to treat paralysis, swellings, corn on skin and intermittent fevers. Flowers are used to reduce or eliminate asthma. The root bark is used to treat fever, destroy or expel parasitic worms, expel mucus and phlegm from the lungs and stimulates bowel movement. The powdered root is used to treat asthma, bronchitis and indigestion.

Other usesPlant sap is used for tanning and making yellow dye.

The stems yield fine, durable fibres that are useful for ropes, carpets, fishing nets and sewing thread.

The hardy, long-lasting flowers are used in floral arrangements in Thailand and strung into leis in Hawaii.

Carpenter Bees (Xylocopa species) collect nectar from the flowers and help in pollination.

Sunbirds use the woolly material attached to the light-weight seeds as nesting material.

Host plantThe female Plain Tiger Butterfly (Danaus chrysippus chrysippus) lays its eggs singly on the underside of leaves. Besides the Crown Flower, the Blood Flower (Asclepias curassavica) is also its host plant. A 2.2 mm long young caterpillar hatches from the egg after 3 days. Within the next 10 days of feeding on the leaves of the Crown Flower, it moults 5 times and grows up to 42 mm in length. The poisonous milky sap in the leaves protect the caterpillar from predators. When fully grown, the caterpillar transforms into a barrel-shaped pupa which is about 20 mm long. The pupa can be green, pink or white in colour. After 5 days of development, an adult Plain Tiger butterfly ecloses or breaks free from the pupal case.

It is also a host plant for the Common Crow butterfly (Euploea core) and the Yellow Aphid (Aphis nerii).

CautionIf swallowed by people and animals, the poisonous sap can cause vomiting and intestinal irritation. The milky sap also causes skin irritation. It is advisable to use gloves when handling it.