Forest 94 - Soap bark tree

Quillaja saponaria

Forest 94 is planned as a forest of Quillaja saponaria, Soap bark tree.

Quillaja saponaria flowers. Photo not from the ArboretumQuillaja saponaria seed pods. Photo not from the Arboretum

Quillaja saponaria tree. Photo not from the Arboretum

Other common names

Chilean soapbark, quillay.

Origin of the species name

Quillaja originated from the Chilean term quilloan, meaning, to wash; saponaria  from Latin sapo meaning soap, in reference to the high content of saponin in the inner bark; and -arium which is a Latin suffix referring to a place of something or a container.



Date planted

October 2017



General description

This is a medium-sized evergreen tree with a rounded dense crown.  It has thick ashy grey bark and smooth, leathery, shiny, oval leaves.  Its white flowers are borne in dense clusters.

Natural distribution and habitat

The species is native to central Chile, where it occurs in dry, poor soils up to altitudes of 2000 metres.  It naturally occurs with the Chilean wine palm (Jubaea chillensis), planted in the Arboretum's Forest 26. Height 18m, spread 10m.

Conservation status

It is not classified as a threatened species.


The inner bark contains saponins which form a lather in water. The powdered bark is used as a substitute for soap, as a food additive and as an ingredient in pharmaceuticals, personal care products, and fire-fighting foam. It has also been used as an additive for photographic films and foaming for drinks. The wood is used cabinetry, and scents derived from the tree are used in perfumes and cosmetics. It has also been used by the Andean people who used it especially as a treatment for various chest problems. It is grown in parks, gardens and as street trees in California.

Planting pattern

A regular grid

Further reading

Encyclopaedia of the Chilean Flora. 2009.