Soapbark(redirected from quillai bark)
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the bark of the soapbark tree (Quilliaja saponaria) of the family Rosaceae. The tree is native to South America. Soapbark contains up to 9 percent saponins. It is used as a lathering agent in preparing emulsions. Soapbark is used instead of soap to wash silk and woolen fabrics.