Siris tree (Fiji)

Tree, up to 25 m, wide-canopied with large, symmetrical, umbrella-shaped crown. Pinkish flowers with white and red stamens, set on heads with around 12-25 flowers per head. These heads may number in the thousands, covering the whole tree. Large branches of the tree tend to break off, particularly during rainstorms. This can be hazardous as the tree is very commonly used for avenue plantation.

Native to Central and South America, but has been widely introduced to South and Southeast Asia, as well as the Pacific Islands, including Hawaii.

The leaves and seeds are used in the treatment of eye problems such as ophthalmia.
The bark is astringent. It is taken internally to treat diarrhoea, dysentery and piles.
The bark is used externally to treat boils.
The flowers are applied locally to maturate boils and alleviate skin eruptions.
The powdered seeds are used to treat scrofula.
Saponin from the pods and roots has spermicidal activity.
Studies have shown that a methanol extraction of the plant is a very effective treatment for diabetes.

The Fijian name “Vaivai” means “watery” (in allusion to the tree’s “rain”).