Pycnanthemum is a genus of herbaceous plants in the mint family (Lamiaceae). Species in this genus are often referred to as "mountain mints" and they often have a minty or thyme-like aroma when crushed. All species of Pycnanthemum are native to the United States and Canada. The center of diversity for the genus is North Carolina with 13 of the 20 species having been collected therein. Nineteen of the 20 species of Pycnanthemum occur in the Eastern US and Canada, and one disjunct species (P. californicum) occurs in California and Oregon.