Which term describes a liquid herb preparation brewed from roots, seeds, or bark?

The term that describes a liquid herb preparation brewed specifically from roots, seeds, or bark is decoction. This method involves boiling the plant materials in water, which allows for the extraction of their medicinal properties effectively. Decoctions are typically made when the ingredients are harder or denser, such as roots or bark, which require a more intensive extraction process compared to softer plant parts.

In contrast, tinctures are made using solvents like alcohol to extract the active compounds from herbs, while extracts often refer to concentrated forms of herbal preparations that can use various methods of extraction, including solvents. The term "tea" is generally used for infusions made with leaves or flowers rather than the harder parts of the plant. Therefore, decoction is the correct term for the specified preparation method involving roots, seeds, or bark.