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.

[1][2][3] The center of diversity for the genus is North Carolina with 13 of the 20 species having been collected therein.

The Greek word "pyknos" has the meaning of "dense", "tight", or "close-packed".

A complicated history of polyploidization paired with cryptic morphologies makes this a challenging group for systematists.