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Sarsaparilla (pronounced SAS-per-il-luh, IPA /ˌsæspəˈɹɪlə/) (Smilax regelii and other closely related species of Smilax) is a perennial trailing vine with prickly stems native to tropical America and the West Indies. Its name (which is zarzaparrilla in Spanish) comes from the Spanish words zarza for "shrub" and parrilla for "little grape vine."
The name sarsaparilla can also refer to a drink made from the roots of the vine. The name "Sasparilla" is also often used but is a common mis-spelling of Sarsaparilla.
Throughout history, Sarsaparilla has been used to cure syphilis. Native Americans used Saraparilla for its medical benefits also. The root of the plant is what is used in medicine. In the nineteenth century, it was believed it could improve one's vigor.
Sarsaparilla contains active principle, Parillin (Smilacin), glucoside, sarsapic acid, sarsapogenin (related to progesterone and used in its synthesis), sarsaponin and starch 
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The vine has a long prickly stem and shiny leaves, and numerous reddish-brown roots up to 3 meters long. Several species of Smilax are used in agriculture, but the Jamaican S. regelii (syn. S. officinalis) is the species preferred for commercial use. Sarsaparilla is also grown in Mexico, Central America and parts of South America. It is also grown in parts of South India, known in Telugu as Sugandhi-pala, in Kannada as sogade beru and in Tamil as Nannaari. The primary uses of sarsaparilla include the flavoring of beverages, and folk medicine.
Before processing, the roots are bitter, sticky, and have a strong odor. They are dried and boiled in order to produce the extract. In beverages, oil of wintergreen or other flavors may be added in order to mask the natural bitterness of the root. Root beer made from sarsaparilla roots is generally more "birchy" than the sarasparilla extract used in the more popular, commercial brands.
A carbonated beverage, made from and called sarsaparilla, is available in many countries.