Pycnanthemum monotrichum
Pycnanthemum monotrichum, commonly known as one-hair mountain-mint, is an extinct species of herbaceous perennial plant in the family Lamiaceae endemic to Southeastern Virginia. Pycnanthemum monotrichum inhabited dry, sandy woodlands and clearings in Virginia's coastal plain. It is a poorly known taxon and may represent a hybrid, or a more abundant species that has been overlooked. Pycnanthemum monotrichum bloomed from July through September and grew up to four feet tall.