Quillaja saponaria, the soap bark tree or soapbark, is an evergreen tree in the family Quillajaceae, native to warm temperate central Chile. In Chile it occurs from 32 to 40° South Latitude approximately and at up to 2000 m (6500 ft) above sea level. It can grow to 15–20 m (50–65 ft) in height. The tree has thick, dark bark; smooth, leathery, shiny, oval evergreen Leaf 3–5 cm long; white star-shaped 15 mm diameter borne in dense ; and a dry fruit with five follicles each containing 10–20 . The tree has several practical and commercial uses.
Habitat
This tree occurs at elevations up to 2000 metres.
[ Encyclopedia of the Chilean Flora, 2009] The species is
drought resistant, and tolerates about −12 °C (10 °F) in its natural habitat.
[J. Taylor. 1990.] Examples of specific occurrences are in central
Chile in the forests of La Campana National Park and Cerro La Campana, in which locales it is associated with the Chilean wine palm,
Jubaea chilensis.
[C. Michael Hogan. 2008] It is often used for
reforestation on
arid .
The plant has been introduced as an ornamental in California, and has been acclimatized in Spain but is rarely cultivated there.
Etymology
Quillaja is derived from the Chilean vernacular name for this species,
culay.
[Gledhill, David (2008). "The Names of Plants". Cambridge University Press. (hardback), (paperback). pp 324, 340]
Saponaria means 'soap-like'.
Uses
The wood is used in cabinetry, and scents derived from the tree are used in perfumes and cosmetics. The inner bark of
Quillaja saponaria can be reduced to powder and employed as a substitute for
soap, since it forms a lather with water, owing to the presence of a
glycoside saponin, sometimes distinguished as
quillaia saponin. The same, or a closely similar substance, is found in soapwort (
Saponaria officinalis), in senega root (
Polygala senega) and in
Smilax regelii; it appears to be chemically related to
digitonin, which occurs in
digitalis.
Uses of the saponins
Soap bark tree has a long history of medicinal use with the
Andes people who used it as a treatment for various chest problems.
[Chevallier, A., The Encyclopedia of Medicinal Plants, 1996] 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.
The bark is the source of
quillaia, the extract of which is used as a
food additive and as an ingredient in
,
, personal care products, fire-fighting foam, and applied as an agricultural spray adjuvant. It is used as an additive in photographic films and as a
foaming agent for drinks.
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.
The saponins of this tree are also considered to have adjuvant properties for vaccine solutions.[Singh, Manmohan, 2007. Vaccine Adjuvants and Delivery Systems, page 193] QS21 adjuvant is a saponin obtainable from Quillaja saponaria extract.
Toxicity
First described by Edwin John Quekett,
Q. saponaria wood and bark is known to contain
, which
George Gulliver found were concentrated along the liber and mesophloeum.
Sources
-
C. Donoso. 2005. Árboles nativos de Chile. Guía de reconocimiento. Edición 4. Marisa Cuneo Ediciones, Valdivia, Chile. 136p.
-
Encyclopedia of the Chilean Flora. 2009. Quillaja saponaria
-
Adriana Hoffmann. 1998. Flora Silvestre de Chile, Zona Central. Edición 4. Fundación Claudio Gay, Santiago. 254p.
-
C. Michael Hogan. 2008. Chilean Wine Palm: Jubaea chilensis, GlobalTwitcher.com, ed. Nicklas Stromberg
-
J. Taylor. 1990. The Milder Garden. Dent
-
Chevallier, Andrew, 1996. The Encyclopedia of Medicinal Plants, Dorling Kindersley, 336p.
-
Singh, Manmohan, 2007. Vaccine Adjuvants and Delivery Systems, John Wiley & Sons, Hoboken, New Jersey, 457 pp.
External links
