Bullbrier, also known as greenbrier, is a type of vine that can be found in different parts of the United States. It is known for its tough, thorny stems, and small white flowers. Though "bullbrier" is its most common name, there are other synonyms for this plant. One of the most popular ones is "catbrier," which is derived from the plant's resemblance to a feline's claws. "Smilax" is also a common name for bullbrier, as this is the plant's genus name. Other synonyms for bullbrier include "hogbrier," "bristly greenbrier," and "bull's-foot vine." These synonyms all refer to the same plant but may vary depending on locality or language.