|A bumblebee on a Monarda flower|
About 16 species, including:
Common names include bee balm, horsemint, oswego tea, and bergamot, the last one due to the leaves' fragrance resembling that of Citrus bergamia fruits. The genus was named for Nicolás Monardes, who wrote a book in 1574 describing plants found in the New World.
Monarda species include annual and perennial upright growing herbaceous plants. Ranging in height from 20–90 cm (8–35 in), the plants have an equal spread, with slender and long-tapering (lanceolate) leaves. The leaves are opposite on the stem, smooth to sparsely hairy, with lightly serrated margins, and ranging from 3 to 6 inches (7 to 14 cm) in length.
The flowers are tubular with bilateral symmetry and bilabiate; with upper lips narrow and the lower ones broader and spreading or deflexed. The flowers are single or in some cultivated forms double, generally hermaphroditic with two stamens. Plants bloom in mid- to late summer and the flowers are produced in dense profusion at the ends of the stem and/or in the stem axils. The flowers typically are crowded into head-like clusters with leafy bracts. Flower colors vary, with wild forms of the plant having crimson-red to red, pink and light purple hues. M. didyma has bright, carmine red blossoms; M. fistulosa—the "true" wild bergamot—has smoky pink flowers. M. citriodora and M. pectinata have light lavender to lilac-colored blooms and have slightly decreased flower quantities. Both species are commonly referred to as "Lemon Mint." "M. didyma" species can grow up to 6 feet tall. Seed collected from hybrids—as with most hybridized plants—does not produce identical plants to the parent. A number of hybrids also occur in the wild.
In all species, the leaves, when crushed, exude a spicy, highly fragrant oil. Of the species examined in one study, M. didyma (Oswego Tea) was found to contain the highest concentration of this oil.
Several bee balm species (Monarda fistulosa and Monarda didyma) have a long history of use as a medicinal plants by many Native Americans including the Blackfoot, Menominee, Ojibwa and Winnebago. The Blackfoot Indians recognized the strong antiseptic action of these plants, and used poultices of the plant for skin infections and minor wounds. A tisane made from the plant was also used to treat mouth and throat infections caused by dental caries and gingivitis. Bee balm is the natural source of the antiseptic Thymol, the primary active ingredient in modern commercial mouthwash formulas. The Winnebago used a tisane made from bee balm as a general stimulant. Bee balm was also used as a carminative herb by Native Americans to treat excessive flatulence. An infusion of crushed Monarda left in boiling water has been used to treat headaches and fevers.
Although somewhat bitter, due to the thymol content in the leaves and buds, the plant tastes like a mix of spearmint and peppermint with oregano. Bee balm was traditionally used by Native Americans as a seasoning for wild game, particularly birds. The plants are widespread across North America and can be found in moist meadows, hillsides, and forest clearings up to 5,000 feet (1,500 m) in elevation.
Monarda plants prefer full sun and moist yet well-drained soil. Plants established in partial shade or filtered sun have higher incidences of rapid horizontal spread and flower less. An aggressive plant in the southeastern United States, bergamots can grow in a wide variety of soil conditions, although in dry soils some species and cultivars can be somewhat stunted. Powdery mildew, rust, and (rarely) tobacco mosaic viruses disrupt established plants on occasion, but the plants are in general highly resistant to most wilts and viruses and are not easily damaged. Slugs however can be a serious pest early in the season, consuming all growth as it first emerges.
Used most frequently in areas in need of naturalization, Monarda is often used in beds and borders to encourage and increase the appearance of hummingbirds, pollinating insects, predatory/parasitic insects that hunt garden pests, and because of oils present in its roots is sometimes used as a companion plant around small vegetable crops susceptible to subterranean pests. Bee balm is considered a good plant to grow with tomatoes, ostensibly improving both health and flavor. While seed should be stratified briefly before starting, seed may be cast directly or started in coldframes or greenhouses at soil temperatures approaching 70 °F (21 °C). Generally, propagation occurs by hardwood and softwood cuttings, root cuttings, layering, and division; the latter, quite frequently, is the most popular method out of necessity: the plant should be divided every 3 to 5 years to reduce spread, keep the central core of the plant healthy, preclude root rot, and improve air circulation about the foliage.
There are over 50 commercial cultivars and hybrids, ranging in color from candy-apple red to pure white to deep blue, but these plants tend to be smaller than wild species, and often developed to combat climatic or pest conditions. Other hybrids have been developed to produce essential oils for food, flavoring, or medicine.
Monarda species are used as food plants by the larvae of some Lepidoptera species including case-bearers of the genus Coleophora including C. heinrichella (feeds exclusively on M. fistulosa), C. monardae (feeds exclusively on Monarda spp) and C. monardella (feeds exclusively on M. fistulosa).
Monarda is in the tribe Mentheae of the subfamily Nepetoideae. Molecular phylogenetic studies of this tribe have been poorly sampled, and relationships within it remain unclear. Blephilia and Pycnanthemum are close relatives of Monarda, but they might not be the closest. Monarda is divided into two distinct subgenera: Monarda and Cheilyctis. These are easily distinguished by several characters.
Selected species 
Formerly placed here 
- Blephilia ciliata (L.) Benth. (as M. ciliata L.)
- Blephilia hirsuta (Pursh) Benth. (as M. ciliata Pursh)
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|Wikispecies has information related to: Monarda|
- "Genus: Monarda L.". Germplasm Resources Information Network. United States Department of Agriculture. 2004-09-10. Retrieved 2011-10-08.
- Raymond M. Harley, Sandy Atkins, Andrey L. Budantsev, Philip D. Cantino, Barry J. Conn, Renée J. Grayer, Madeline M. Harley, Rogier P.J. de Kok, Tatyana V. Krestovskaja, Ramón Morales, Alan J. Paton, and P. Olof Ryding. 2004. "Labiatae" pages 167-275. In: Klaus Kubitzki (editor) and Joachim W. Kadereit (volume editor). The Families and Genera of Vascular Plants volume VII. Springer-Verlag: Berlin; Heidelberg, Germany. ISBN 978-3-540-40593-1
- W. Mark Whitten (Mar., 1981), "Pollination Ecology of Monarda didyma, M. clinopodia, and Hybrids (Lamiaceae) in the Southern Appalachian Mountains", American Journal of Botany 68 (3): 435–442, doi:10.2307/2442781, JSTOR 2442781
- L. Alan Prather, Anna K. Monfils, Amanda L. Posto, and Rachel A. Williams (2002), "Monophyly and Phylogeny of Monarda (Lamiaceae): Evidence from the Internal Transcribed Spacer (ITS) Region of Nuclear Ribosomal DNA", Systematic Botany 27 (1): 127–137, doi:10.1043/0363-6445-27.1.127
- Edwin Rollin Spencer (1974), All About Weeds, Courier Dover, p. 218, ISBN 0-486-23051-1
- Edible and Medicinal Plants of the West, Gregory L. Tilford, ISBN 0-87842-359-1
- Mazza, G., F.A. Kiehn, and H.H. Marshall (1993), "Monarda: A source of geraniol, linalool, thymol and carvacrol-rich essential oils", in J. Janick and J.E. Simon, New crops (Wiley, New York): 628–631
- "RHS Plant Selector - Monarda 'Beauty of Cobham'". Retrieved 24 May 2013.
- "RHS Plant Selector - Monarda 'Gardenview Scarlet'". Retrieved 24 May 2013.
- "RHS Plant Selector - Monarda 'Marshall's Delight'". Retrieved 24 May 2013.
- "RHS Plant Selector - Monarda 'Squaw'". Retrieved 24 May 2013.
- "RHS Plant Selector - Monarda 'Talud'". Retrieved 24 May 2013.
- "RHS Plant Selector - Monarda 'Violet Queen'". Retrieved 24 May 2013.
- P. Olof Ryding. 2010. "Pericarp structure and phylogeny of tribe Mentheae (Lamiaceae)". Plant Systematics and Evolution 285(3-4):165–175 doi:10.1007/s00606-010-0270-9
- Rainer W. Scora. 1967. "Interspecific relationships in the genus Monarda (Labiatae)". University of California Publications in Botany 41(1):1–71.
- "Monarda". Integrated Taxonomic Information System. Retrieved 2011-10-09.
- "GRIN Species Records of Monarda". Germplasm Resources Information Network. United States Department of Agriculture. Retrieved 2011-10-08.