White snakeroot | |
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Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Ageratina |
Species: | A. altissima |
Binomial name | |
Ageratina altissima (L.) King & H.E.Robins. | |
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Natural range in North America | |
Synonyms [2] | |
List
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Ageratina altissima, also known as white snakeroot, [3] richweed, [3] or white sanicle, [4] is a poisonous perennial herb in the family Asteraceae, native to eastern and central North America. An older binomial name for this species is Eupatorium rugosum, but the genus Eupatorium has undergone taxonomic revision by botanists, and some species once included in it have been moved to other genera.
Plants are upright or sometimes ascending, growing to 1.5 metres (4.9 ft) tall, producing single or multi-stemmed clumps in mid to late summer and fall. Stems are smooth with opposite leaves spaced well apart, with each pair of leaves positioned at a 90-degree angle from the pair above and below (decussate). The upper part of the plant has multiple branches, which usually appear in opposite pairs. Leaves have sharply serrated margins and are up to 15 centimetres (6 in) long. [5]
At the end of the upper branches, flat-topped panicles or compound corymbs of white flower heads appear, measuring 5–15 centimetres (2–6 in) across. The flowers are a clean white color and after blooming, small seeds with fluffy white tails are released to blow in the wind. The plant can spread either by the wind dispersal of its seeds or by rhizomes. [6]
There are two different varieties: Ageratina altissima var. altissima and Ageratina altissima var. roanensis (Appalachian white snakeroot); they differ in the length of the flower phyllaries and shape of the apices. [7] [8]
A altissima is native to the central and eastern United States, from Texas in the west to Maine in the east and north, and Florida in the south. The species is also native in Canada in Quebec, Ontario, and the Northwest Territories. [9] The species is adaptive to different growing conditions; it is found in woods and brush thickets and also in shady areas with open bare ground, and it can be weedy in shady landscapes and hedgerows. [10]
The plant blooms in the fall, from July to October. [11] Its nectar attracts many species of butterflies and moths, bees, wasps, and flies. [6] It is a larval host for a few varieties of moths, including the Clymene moth ( Haploa clymene ), Leucospilapteryx venustella , and the hitched dart moth ( Melanchra adjuncta ). [12]
This species is host to the following insect induced galls:
White snakeroot contains the toxin tremetol; when the plants are consumed by cattle, the meat and milk become contaminated with the toxin. When milk or meat containing the toxin is consumed, the poison is passed on to humans. If consumed in large enough quantities, it can cause tremetol poisoning in humans. The poisoning is also called milk sickness, as humans often ingested the toxin by drinking the milk of cows that had eaten snakeroot. [13] Although 80% of the plant's toxin, tremetone, decreases after being dried and stored away for 5 years, its toxic properties remain the same. [14]
During the early 19th century, when large numbers of European Americans from the East, who were unfamiliar with snakeroot, began settling in the plant's habitat of the Midwest and Upper South, many thousands were killed by milk sickness. Notably, milk sickness was possibly the cause of death in 1818 of Nancy Hanks Lincoln, mother of Abraham Lincoln. [15]
It was some decades before European Americans traced the cause to snakeroot, although today Dr. Anna Pierce Hobbs Bixby is credited with identifying the plant in the 1830s. Legend has it that she was taught about the plant's properties by a Shawnee woman. [16] [17]
In addition to cattle, the plants are also poisonous to horses, goats, and sheep. Signs of poisoning in these animals include depression and lethargy, placement of hind feet close together (horses, goats, cattle) or held far apart (sheep), nasal discharge, excessive salivation, arched body posture, and rapid or difficult breathing.[ citation needed ]
A cultivar, sold under the name Eupatorium rugosum 'Chocolate', is grown in gardens for its dark-tinted foliage. The darkest color, which is a chocolate black, occurs in plants grown in a sunny location. The plants are shade-tolerant and do best in moist soils. [18] More recently, the plant can be found under the correct species name.
Ageratina is derived from Greek meaning 'un-aging', in reference to the flowers keeping their color for a long time. This name was used by Dioscorides for a number of different plants. [19]
Altissima means "the tallest", and probably indicates that this is the tallest species in its genus. [19]
Eupatorium is a genus of flowering plants in the family Asteraceae, containing from 36 to 60 species depending on the classification system. Most are herbaceous perennials growing to 0.5–3 m (1.6–9.8 ft) tall. A few are shrubs. The genus is native to temperate regions of the Northern Hemisphere. Most are commonly called bonesets, thoroughworts or snakeroots in North America. The genus is named for Mithridates Eupator, king of Pontus.
Rudbeckia laciniata, the cutleaf coneflower, is a species of flowering plant in the family Asteraceae. It is native to North America, where it is widespread in both Canada and the United States. Its natural habitat is wet sites in flood plains, along stream banks, and in moist forests. Common names other than cutleaf coneflower include cutleaf, goldenglow, green-headed coneflower, tall coneflower, sochan and thimbleweed.
White snakeroot is a common name for several flowering plants in the aster family, Asteraceae, and may refer to:
Ageratina shastensis is a species of snakeroot which is endemic to Shasta County, California. It is known by the common names Mt. Shasta snakeroot and Shasta eupatorium.
Eupatorium altissimum, with the common names tall thoroughwort and tall boneset, is a perennial herbaceous plant in the Asteraceae family with a native range including much of the eastern and central United States and Canada. It is a tall plant found in open woods, prairies, fields, and waste areas, with white flowers that bloom in the late summer and fall.
Eutrochium maculatum, the spotted joe-pyeweed, is a North American species of flowering plant in the family Asteraceae. It is widespread through much of the United States and Canada. It is the only species of the genus Eutrochium found west of the Great Plains.
Ageratina riparia, commonly known as mistflower, is a species of flowering plant in the family Asteraceae, native to Mexico. The species is widely adventive and has spread to Cuba, Jamaica, and other parts of the Caribbean. It has also been introduced as an ornamental plant and naturalized in a variety of regions, including parts of Hawaii, South Africa, Southeast Asia, Macaronesia, Oceania, Peru, and the Indian subcontinent. In tropical climates, A. riparia is highly invasive and a variety of control methods have been developed to reduce its spread.
Ageratina herbacea is a North American species of flowering plants in the family Asteraceae known by the common names fragrant snakeroot and Apache snakeroot. It is native to desert regions of the southwestern United States and northern Mexico. It grows in rocky slopes in conifer forests and woodlands.
Ageratina occidentalis is a species of flowering plant in the family Asteraceae known by the common name western snakeroot or western eupatorium. It is native to the western United States where it grows in several types of habitat. It is found in California, Oregon, Washington, Idaho, Montana, Nevada, and Utah.
Ageratina adenophora, commonly known as Crofton weed, is a species of flowering plant in the family Asteraceae native to Mexico and Central America. Originally grown as an ornamental plant, it has become invasive into farmland and bushland worldwide. It is toxic to horses, which develop a respiratory disease known as Numinbah horse sickness after eating it.
Veratrum hybridum is a species of flowering plant in the Melanthiaceae known by the common names slender bunchflower and crisped bunchflower. Many publications use the synonyms Melanthium latifolium and Veratrum latifolium, but the "hybridum" epithet is 9 years older than the "latifolium," so Veratrum hybridum is now the accepted name.
Ageratina luciae-brauniae is a species of flowering plant in the family Asteraceae known by the common names Lucy Braun's snakeroot and rockhouse white snakeroot. It is native to the eastern United States, where it is limited to the Cumberland Plateau of Kentucky and Tennessee. It may also occur in South Carolina but these reports are unconfirmed.
Anna Pierce Hobbs Bixby, sometimes spelled Bigsby, born Anna Pierce, was a midwife, frontier doctor, dentist, herbologist, and scientist in southern Illinois.
Orbexilum pedunculatum, commonly known as Sampson's snakeroot, is a species of flowering plant in the legume family. It is native primarily to the Southeastern United States where it is found in prairies and savannas, often in acidic soil. It is a perennial that produces racemes of flowers in early summer.
Tremetone is a constituent of the toxic compound tremetol, found in snakeroot, that causes milk sickness in humans and trembles in livestock. Tremetone is the main constituent of at least 11 chemically related substances in tremetol. Tremetone is toxic to fish, but not to chicken, and is therefore not the major toxic compound in tremetol. Tremetol can be found in a number of different species of the family Asteraceae, including snakeroot and rayless goldenrod.
Ageratina aromatica, also known as lesser snakeroot and small-leaved white snakeroot, is a North American species of plants in the family Asteraceae. It is widespread and common across much of the eastern and southern United States from Louisiana to Massachusetts, as far inland as Kentucky and Ohio.
Ageratina jucunda, called the Hammock snakeroot, is a North American species of plants in the family Asteraceae. It is found only in the southeastern United States, in the states of Georgia and Florida. It is a perennial herb growing up to 3 ft (0.91 m) tall.
Ageratina paupercula, called the Santa Rita snakeroot, is a North American species of shrubs or perennial herbs in the family Asteraceae. It is found only in the states of Arizona, Sonora, Chihuahua, Durango, Nayarit, and Jalisco.
Ageratina rothrockii is a North American species of plants in the family Asteraceae. It is found only in the southwestern United States in the states of Arizona, New Mexico, and Texas, as well as the states of Sonora, Coahuila, Chihuahua, and Durango in Mexico.
Ageratina wrightii is a North American species of plants in the family Asteraceae. It is native to the southwestern United States and northern Mexico.