Wouter Klein at JSTOR Daily:
When European naturalists explored the plants of the New World in the sixteenth century, they tended to relate new species to better-known plants whenever they could. Sarsaparilla is a case in point. Smilax species found in America were recognized as variants of Smilax aspera and therefore also began to be called sarsaparilla. Nicolás Monardes (1493–1588) described different kinds of American sarsaparilla in his work Historia medicinal de las cosas que se traen de nuestras Indias Occidentales (1565). His descriptions carried a commercial touch. For instance, he tried to convince his readers that the whitish sarsaparilla from Honduras was better than the black variety from Mexico. Similarly, he aimed to embed the new American kinds of sarsaparilla in the traditional framework of European medicine. When American sarsaparilla began to be used in European medicine around 1545, physicians first administered it as a broth to be taken in the morning, the same way as it was used by Native Americans at the time. Monardes, however, argued that it should be given in a syrup, a conventional mode of administration for his European readers.
more here.