Purple Horsemint, Lemon Beebalm

Purple Horsemint
Common names: Lemon beebalm, Purple horsemint, Lemon mint, Plains horsemint, Lemon horsemint, Horsemint, Purple lemon mint (wildflower.org)
Scientific name: Monarda citriodora
Family: Lamiaceae -- Mint family 
Genus: Monarda L. -- beebalm

As you drive by a patch of lemon beebalm/purple horsemint your eye is immediately drawn to it.  The tall stemmed bloom spikes look like bottle rockets ready to launch or tiny exotic parasols.  They gently sway in unison with any small breeze. When the dried leaves of the Monarda citriodora are crushed they fill the air with a fresh lemon scent which is the reason for the lemon mint common name.

Purple Horsemint

The Monarda citriodora species is from the mint family (Lamiaceae) and of the genus Monarda or beebalm. The genus is named after Nicolas Monardes, a 16th century author who cataloged numerous plants for their medicinal uses. Citriodora is most likely derived from the Latin citrus (loosely related to "lemon tree") and odora meaning "having a fragrance of."
 
Several references indicate Monarda citriodora contains citronellol which is used in natural insect repellents, but the one phytochemical resource I found did not show Monarda citriodora containing the citronellol chemical(https://phytochem.nal.usda.gov/phytochem/plants/show/1330).  Two other plants with similar names are lemonbalm - also sometimes called lemon mint - (Melissa officinalis) and lemon eucalyptus (Eucalyptus citriodora) both contain citronellal from which citronella oil can be made. The major source of commercial citronella oil is from citronella grass -Cymbopogon nardus. Monarda citriodora does contain 1,8-Cineole (Eucalyptol) which is listed as a "insectifuge" (natural insect repellent) by Dr. Duke's Phytochemical and Ethnobotanical Databases (https://phytochem.nal.usda.gov/phytochem/plants/show/1330).

Lemon beebalm (Monarda citriodora) is available in seed from Native American Seed (https://www.seedsource.com/catalog/de...product_id=1006) and Wildseed Farms.  Lemon beebalm makes a very lovely and fragrant addition to a wildflower haven garden. In addition to bees and butterflies it will also attract hummingbirds to your garden.
Monarda citriodora has been used as flavoring in teas, wines, salads, jellies and fruit preserves and the dried leaves in potpourris.
Monarda citriodora like its relatives in the Monarda genus contains thymol, an antiseptic used in mouthwashs. Monarda citriodora also contains citral which is likely the substance that gives Monarda citriodora the citrus-lemon scent. 

Some of the routes where I have found it:
In Texas, you can find Monarda citriodora most anywhere in the Hill Country to North Central Texas.

  • RR-580 at Bend, Texas
  • RR-962
  • RR-337 east of Vanderpool

Blooms mostly: May through July, but can be extended with extra watering.
Counties where I have found it: Bandera, Bexar,Blanco, Gillespie, Kerr, Llano

References

https://en.wikipedia.org/wiki/Citronella_oil
https://en.wikipedia.org/wiki/Citronellol
https://en.wikipedia.org/wiki/Eucalyptol (1,8-cineole)
https://phytochem.nal.usda.gov/phytochem/plants/show/1330
http://www.wildflower.org/plants/result.php?id_plant=MOCI
https://en.wikipedia.org/wiki/Monarda_citriodora

Other images

Purple Horsemint
RR-1871

http://www.pbase.com/richo/image/163267355
http://www.pbase.com/image/29636027
http://www.pbase.com/image/29781488
http://www.pbase.com/image/29781489
http://www.pbase.com/image/29782948

More about Monarda spp. : https://www.wildflower.org/magazine/n...lo-name-monarda

Edited: Changed sentence about the chemical composition.  The phtochemical database does not show Monarda citriodora containing the citronellol chemical.