The tree has thick, dark bark; smooth, leathery, shiny, oval evergreen leaves 3–5 cm long; white star-shaped flowers 15 mm diameter borne in dense corymbs; and a dry fruit with five follicles each containing 10–20 seeds.

Soap bark tree has a long history of medicinal use with the Andean people who used it as a treatment for various chest problems.

[5] The saponin content of the bark helps to stimulate the production of a more watery mucus in the airways, thus facilitating the removal of phlegm through coughing.

[5] The bark is the source of quillaia, the extract of which is used as a food additive and as an ingredient in pharmaceuticals, pesticides, personal care products, fire-fighting foam, and applied as an agricultural spray adjuvant.

The saponins in Quillaja Extract are also used as the active ingredient in commercial pesticides to inhibit the growth of pathogenic fungi and nematodes in ornamental plants, food crops and turfgrass.