Bergamots all have flowers in dense heads with the stamens protruding.
Stems: Purple Bergamot grows upwards to 3+ feet high on typical 4-angled mint family green stems (reddish with full sun at maturity) that branch in the upper half and are mostly hairless though they can have some gray hair at the nodes and on the stem angles.
Leaves are opposite, stalked, lance shaped with a triangular base, and a main rib-vein with branched side veins curving toward the leaf margin which is serrated. Teeth are less noticeable or absent on upper leaves. Lower leaves are larger, with more pronounced teeth, longer stalks and can have a pair of minor leaflets at the base of the stalk. Stalks and leaf surfaces of all leaves have fine hair. The green parts of the plant have a distinctive aroma of oregano when crushed. The Bergamot that is an ingredient in Earl Gray Tea is not this plant, but Mentha citrata.
Inflorescence: The inflorescence is a single dense flower head, 1 to 3 inches wide, on one of many branching stems, but sometimes appear from an upper leaf axil.
Flowers: Flowers are tubular, reddish purple in color, with corollas that have one elongated lip forming a tube that surrounds and protects the 2 stamens and the style, but they protrude slightly above that upper lip. Stamens have lighter color anthers with a darker marginal line and the style has fine white hair. There is also a purplish hair on the outside of the corolla tube. Flowers open from the center of the head first and progress to the outer edge. Under the flower head are green bracts that turn purplish in color, while some smaller bracts under them remain green. The flower stem has fine white hair as do the margins of the bracts.
Seeds are a small black dry nutlet. Dry seeds need 3 months of cold storage before planting in the early spring.
Habitat: Purple Bergamot likes full sun with moist to somewhat dry conditions and slightly acidic soil. The plant grows from a rhizomatous root system that produces multiple stems in a cluster. Long-tongued bees and butterflies love the plant.
Names: The genus name, Monarda, is an honorary for Spanish botanist Nicholas Monardes (1493-1588) who published a book in several editions on medicinal plants of the new world. The species media, means 'intermediate' or 'middle', the use here being obscure. The author name for the plant classification - ‘Willd.’ is for Carl Ludwig Willdenow (1765-1812), German botanist, a founder of the study of the geographic distribution of plants. He was director and curator of the Botanic Garden of Berlin.
Comparison: There are not many plants of Purple Bergamot in the Upland Garden compared with the proliferation of Wild Bergamot, M. fistulosa, which differs from this plant by its lighter pink to lavender color. Purple Bergamot tends to bloom earlier than Wild Bergamot. The structure of the two plants is similar. There are ornamental cultivars available from the nursery trade which could ultimately escape to the wild. These usually resemble M. media and M. fistulosa except in flower color - the most common cultivar comes from Monarda didyma and is the deep red one called called 'Raspberry Wine'.
Above: 1st photo - The flower stem of Purple Bergamot. Note the upper opposite leaves are mostly without teeth. 2nd photo - A flower head showing the reddish-purple color of the flower corollas which have one lip partially enclosing the 2 stamens and style.
Below: Flowers open first in the center of the head, them proceding outward. Here you see flowers around the base of the head not yet open.
Below: 1st photo - the base of the flower showing the small green bracts and above them the larger ones that turn a purplish shade and have marginal hair. 2nd photo - an upper stem leaf.
Below: A lower stem leaf. Note the the angles of the stem and the hair on the stalk, leaf margin, and stem angles.
Below: A grouping of Purple Bergamot in the Upland Garden next to some seed pods of White False Indigo (Baptisia alba)
Below: A comparison of -1st photo - Wild Bergamot, M. fistulosa, and 2nd photo - the cultivar 'Raspberry Wine', Monarda didyma.
Notes: Purple Bergamot is not native or generally found in the State. It is a plant native to the eastern United States with Illinois it's most westward known native range. In Canada it is known only from Ontario. It was not included on Martha Crone's 1951 census of Garden plants. It's date of appearance in the Garden can probably be fixed as 1971, when Gardener Ken Avery wrote in the Friends' newsletter, The Fringed Gentian™ that "a clump of Purple Bergamot just appeared in the Garden this year!"
Eloise Butler wrote of our native Wild Bergamot and her comments aptly apply here also: "Mrs. Mable Osgood Wright, in her The Garden, You and I, describes a fascinating garden designed by an invalid lady, in which nothing was admitted but plants with fragrant flowers or leaves. In such a garden, the mints would abound, and among them would be Monarda fistulosa, the Wild Bergamot, that now enlivens the borders of woods and meadows with large clumps of bright lavender bloom. Abundant as it is, we are never ready to cry “Hold! Enough!” For, besides its delicate perfume, it delights the eye as well. This plant will at once remind one of the cultivated, red-flowered bee balm or Oswego tea (Monarda didyma). The mints may be recognized by their square stems, two-lipped flowers, and usually aromatic odor." Published July 23, 1911, Minneapolis Sunday Tribune
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"