Boneset is a native erect perennial forb reaching up to 5 feet high, on stout stems that have long spreading hairs, the stems with minor branching near the top and branching within the floral array.
The leaves are opposite, up to 8 inches long, 4x as long as wide, tapering to a pointed tip, toothed along the margins, and with a wide base distinctively surrounding the stem so as to appear that the stem pierced a single leaf at the midpoint of two blades. The pinnate vein network is very conspicuous. The leaf surfaces have fine hair, particularly the underside which also can have fine gland-dotting.
The floral array is composed of broad branching clusters at the top of the stem- basically a compound corymb as each cluster is in corymb form (somewhat flat-toped due the flower stalks of varying length). Each flower in the cluster contains 7 to 11 small white florets similar to the disc florets of the asters. Ray florets are lacking.
The flowers are about 1/2 inch across and are composed of 7 to 11 florets, each of which is about 1/6 to 1/5 inch across with a white corolla that has 5 spreading triangular lobes at the throat. The styles of the florets are much longer than the corollas and with a bifurcated tip are quite conspicuous. The five stamens surround and are appressed to the style. Anthers are a brownish color at maturity. The outside of the flowerhead is surrounded by 7 to 10 phyllaries in one or two series, each oblong with whitish pointed tips and surfaces finely hairy with glands. Flower stalks and corymb stalks are also hairy.
Seed: Fertile flowers produce a dry dark brown ribbed narrowly conic shaped cypsela, 1.5 - 2 mm long, with a fluffy pappus attached for wind dispersion and a pointed tip at the opposite end. Seeds require 30 days of cold stratification and light to break dormancy.
Habitat: Boneset is a plant of sunny, wet to wet-mesic areas, growing from a rhizomatous root system which allows vegetative growth to form colonies. It can withstand standing water for a short period of time. It can be a long-lived plant.
Names: Boneset shares the generic name Eupatorium, with about 40 other species, named after Mithridates Eupator the ruler of Pontus in old Asia Minor, who lived from 135-63 BC. He was the sixth in his line and was aware that the principal method of disposing of ones enemies in those days was by poison so he began using plants in his medicine and in his personal quest to become insensitive to poisons. By ingesting a slight amount of plant poisons each day along with various plant based antidotes, Mithridates was able to build an immunity to many poisons, such that when he wished to commit suicide following his defeat, poison would no longer work and he had to have a military associate slay him by the sword. Long a friend of Rome, he had gone his own way, defeating two prominent Roman generals in the process, but in 63 BC he was finally defeated in his own kingdom of Pontus by Gnaeus Pompeius Magnus, which battle earned Pompey the title “Pompey the Great,” who then was later associated with Julius Caesar in the First Triumvirate.
The species name, perfoliatum, is Latin and refers to the stem piercing the leaf. The common name of Boneset comes from the use of the plant in treating what was known as “break bone fever” (dengue). See medicinal notes below. The author name for the plant classification - 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: Boneset is the only species in our area with multiple clusters of small white flowers and with opposite leaves that clasp the stem. There are 2 other species of Boneset found in Minnesota: Eupatorium altissimum, Tall Boneset and Upland Boneset, Eupatorium sessilifolium. Eupatorium altissimum has leaves that have 3 main veins from the base, not a pinnate pattern, lack teeth on the lower edges, are sessile but do not surround the stem, and the florets number 5. Eupatorium sessilifolium has leaves that also have a pinnate vein pattern but are sessile but not clasping, the florets are 5 per head. White Snakeroot, Ageratina altissima, has similar looking corymbs, but has broad stalked leaves and prefers shade.
Above: The floral array is composed of broad branching clusters at the top of the stem, each cluster in corymb form. Stems are very hairy and the opposite leaves surround the stem.
Below: 1st photo - Individual florets when open, have five pointed and spreading lobes at the throat. The stamens have dark anthers and surround the white style. 2nd photo - The outside of the flower head has 7 to 10 oblong phyllaries covered with fine hair, as are the flower stalks and the cluster stalks.
Below: The inflorescence becomes a fluffy brownish-white series of maturing flower heads. Each dry cypsela is ribbed and has a fluffy white pappus attached for wind dispersion.
Notes: Boneset is indigenous to the Garden area. Eloise Butler catalogued it on Sept. 6, 1907. In Sept. 1918 she noted bringing in a pink colored specimen from Washburn Park, Minneapolis. Martha Crone planted Boneset in 1946. Boneset is native to most of the counties in Minnesota with most exceptions being in the SW quadrant. Its range in North America is the eastern 2/3rds of the continent.
Eloise Butler wrote of this plant: "Three sister composites - eupatoriums - grow together in the meadows. The homeliest, E. perfoliatum, has rather a coarse aspect, and its dull gray flowers scarcely command a glance from the passerby. Yet, under closer observation, they will not fail to please and will not be ignored when properly arranged in a vase. Every natural growth has a beauty of form, if not of color, that needs only to be seen to be appreciated. As Emerson said, 'We are immersed in beauty, but our eyes have no clear vision.' Folks brought up in the old-fashioned way have a bitter memory of this Eupatorium under the name of Throughwort or Boneset, which in the spring was dealt out copiously to every member of the household, as a thorough remedy to prevent or to remove influenzal bone aches and, in general, 'to purify the blood.' " Published Aug. 6, 1911, Minneapolis Sunday Tribune. [Note: Eloise refers to the three sister composites- Joe Pye Weed and White Snakeroot. Those two have recently been reclassified into the genus Eutrochium and Ageratina respectively.]
Lore and Uses: In pre-modern medicine Boneset was used in treating what was known as “break bone fever” (dengue) and for that use it was superior to the use of Joe Pye Weed. All parts of the plant are active but the listed medicinal parts are the tops and leaves, which can be gathered after flowering has begun. They contain a volatile oil, tannic acid and Eupatorin, which is a bitter glucosidal principle (glycoside). As a medicinal remedy it is a stimulant, tonic, emetic, antispasmodic and diaphoretic. Unlike Joe Pye Weed, it is not a diuretic. It was a legendary plant among the native Americans and early European settlers for its capacity to cause profuse perspiration to treat fevers and also to loosen the bowels. This must be administered as an infusion, taken as warm as the person can stand; it then acts as an emetic and diaphoretic and eventually evacuation of the bowels (Ref. #7). When taken cold it is a tonic.
Crushed leaves and flowers could be dried to make a hot tea taken as a cold remedy. As any tincture or infusion is bitter to the taste and thus disliked by children, it was made into a syrup composed of Boneset, ginger and anise and given to them as a cough remedy. Densmore (Ref. #5) reports its use as a charm by the Chippewa as follows: Root fibers were combined with common milkweed and applied to a whistle used for calling deer.
The plant parts were listed in the U. S. Pharmacopoeia for almost 100 years and then in the National Formulary 1926 to 1950. Boneset is probably the plant that had the most extensive medicinal use in the United States.
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.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"