Whiteleaf Mountain Mint (Pycnanthemum albescens)

I love finding patches of this wonderfully aromatic mountain mint on Ozarkedge.  I found the first patch in the fall. My husband and I were working on one of our trails through the woods and I was hauling off some dead tree limbs. Right at the base of a big oak, I spotted the the dried stems of a plant I had only read about. When I knelt in front of it and crushed a few leaves, I was sure I had found my first mountain mint on the property. The peppermint aroma is just delightful and is as strong in the dried winter leaves as it is in the green summer leaves.

Latin Name/Common Name-  The common name of  Mountain Mint is shared by several other members of the same family, so it’s important to learn the scientific name- Pycnanthemum albescens. The most distinguishing common name I found is Whiteleaf Mountain mint. The word ‘Pycnanthemum’ means densely flowered or dense blossom. The word alba means white and scens relates to the pubescent nature of the leaves and stem.

Bloom Color- Pycnanthemum albescens flowers first appear as a silvery cast to the upper leaves. At first glance, you might think the plant is developing powdery mildew. What you are seeing are the leaf-like bracts just beneath the developing flowers.

Mountain Mint with flowers not quite open
Mountain Mint with flowers not quite open

The flowers are white with faint purple dots.

Mountain Mint flower August 1st
Mountain Mint flower August 1st

Description- Pycnanthemum albescens is a perennial that grows about 1-4 freet tall. On Ozarkedge it grows between 2-3 feet tall. The plants are distinctive in having a whitish edge to the upper leaves developing in July. The opposite leaves are pubescent and soft. It only takes a slight bruising of the leaves to fill the surrounding air with a minty aroma. The stem is hairy. The flower shape is unique. It doesn’t look like a typical flower. The silvery bracts are much larger than the dense flower heads with their tiny petals.

Mountain Mint just starting to fade to white in mid July
Mountain Mint just starting to fade to white in mid July
Mountain Mint with silvery bracts and flowers August 1
Mountain Mint with silvery bracts and flowers August 1

The distinctive shape (and aroma) through winter makes the plant easy to identify during any season. In the spring, the new leaves push up from the earth adjacent to the dried stems from the previous year. Eventually, the old stems fall and by late spring, the new growth has replaced them. The spring growth has a purple tinge to the veins and undersides of the leaves. The new spring leaves look quite different than the mature summer leaves, but if you bruise one, the minty smell is right there to let you know you’ve got the right plant.

Close up of Mountain Mint emerging March 17
Close up of Mountain Mint emerging March 17

Bloom Time- Pycnanthemum albescens blooms from July to September.

Habitat- The name, Mountain Mint, is a bit misleading as this lovely plant doesn’t really have anything to do with mountains. On Ozark Edge, I’ve found it growing on a wooded hillside in dry, rocky woods as well as at the base of a hill not far from a creek bed. It also grows along the wooded edge. You may not notice it mixed in with the other vegetation until it starts developing its white bracts in July.

Mountain Mint in upland woods
Mountain Mint in upland woods
Mountain Mint growing at the base of a large oak tree.
Mountain Mint growing at the base of a large oak tree.

I’ve read that Pycnanthemum albescens can take some sun and I plan to collect some seeds and try it out. This truly is a beautiful plant and would be distinctive in any garden because of the upper silver leaf bracts and wonderful aroma. If you want to grow it, be sure to collect the seed rather than dig the wild plant. Read the Endangered List below  to find out about the unfortunate state of this plant in the wild.

What’s Growing Nearby?- I’ve seen Desmodium rotundifolium (Dollar leaf), Desmodium perplexum (Tick trefoil) and Monarda bradburiana growing nearby. Mountain mint seems to like growing underneath a tree–especially oak.

   Monarda bradburiana  Desmodium perplexum  Desmodium rotundifolium

Endangered List- The USDA plants database (http://plants.usda.gov/java/profile?symbol=PYAL) lists Pycnanthemum albescens as endangered in both Kentucky and Illinois. This list needs to be updated though, since it has sadly gone from being endangered to extirpated in Illinois, where it was last found in the wild in 1973. Recent searches have not relocated the species anywhere in the state.

The latest update from Kentucky is from 2006, where it’s known range was restricted to just one county in the state. It has been threatened through forest clearing and by competition from exotic plants (alien plants).

Mountain mint plant in bloom late July
Mountain mint plant in bloom late July

Interesting Tidbits- Pycnanthemum albescens has been used to make leaf tea.

Mountain Mint flowers
Mountain Mint flowers