Overview

Comprehensive Description

Comments

The flowers of Seneca Snakeroot have a bud-like appearance even when they are open. For this species, there is some significant variability in the width of the leaves and the size of the seed capsules and their seeds. In Illinois, other Polygala spp. (Milkworts) have non-white flowers or their leaves are whorled, rather than alternate. They also tend to be smaller in size overall than Seneca Snakeroot. Therefore, it is fairly easy to distinguish Seneca Snakeroot from these other species. This species also superficially resembles some Persicaria spp. (Smartweeds) with white flowers, however the latter have conspicuous ochreae (sheaths) that wrap around their stems and they prefer wetter habitats. Seneca Snakeroot also has floral racemes that superficially resemble those of Orbexilum pedunculatum (Sampson's Snakeroot), but the latter species can be easily distinguished by its trifoliate leaves.
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Description

This perennial wildflower is 1-1¾' tall, producing one or more leafy stems from the root system that are erect to ascending. These stems are light green to reddish purple, terete, and usually unbranched; they are rough-canescent above and mostly glabrous below. Alternate leaves occur along these stems that are variable in size
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Distribution

Range and Habitat in Illinois

Seneca Snakeroot is occasional in northern and central Illinois, while in the southern part of the state it is largely absent (see Distribution Map). Habitats include upland gravel prairies, hill prairies, savannas, wooded slopes along rivers or lakes, and abandoned fields. Occasional wildfires and other kinds of disturbance are beneficial if they reduce competition from woody vegetation.
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National Distribution

Canada

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

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National Distribution

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

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Global Range: Canada from Quebec and New Brunswick to British Columbia; southward in the U.S. east of the Rocky Mountains (except Montana) to Wyoming and Oklahoma, eastward (except Alabama) to Georgia, and northward through New England (except New Hampshire) to Maine (Kartesz 1999, Fernald 1970).

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Ecology

Habitat

Range and Habitat in Illinois

Seneca Snakeroot is occasional in northern and central Illinois, while in the southern part of the state it is largely absent (see Distribution Map). Habitats include upland gravel prairies, hill prairies, savannas, wooded slopes along rivers or lakes, and abandoned fields. Occasional wildfires and other kinds of disturbance are beneficial if they reduce competition from woody vegetation.
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Comments: Chiefly found in calcareous woods, shores and prairies, often on rocks, gravels or thin soils, and sometimes in wet or boggy habitats.

According to Fernald (1970), this species is in dry rocky or gravelly, chiefly calcareous areas. Hinds (1986) gave its habitat as calcareous woods and shores. Gleason and Cronquist (1991) stated that the species occurs in dry or moist woods and prairies, often in calcareous soil. Voss (1985) reported that whereas in northern Michigan it occurs on calcareous rocks and gravels in openings and at borders of coniferous woods, in southern Michigan it occurs in a diversity of wooded, boggy, swampy, rocky, or "even" prairie-like habitats, shores and banks. The species is in the southern two thirds of Manitoba in thickets, prairie, and clearings (Scoggan 1957). Douglas et al. (1990) report that in northeastern British Columbia in steppe vegetation and montane zones, it is rare in moist to mesic sites. Van Bruggen (1976) reported that the species occurs on sterile soil or rocky outcrops in the Black Hills of South Dakota. In Indiana, Deam (1940) stated that it usually occurs on wooded slopes along streams and lakes, but rarely in the open in a prairie habitat. For the Southeast, Duncan and Foote (1975) said that it occurs in dry places, thin woods and rocky soils, which often are calcareous.

Manitoba Agriculture and Food (2000) report that the species is found in open woods, along roadsides, and in prairie areas, and that it is often found in disturbed areas.

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Associations

Faunal Associations

Various small to medium-sized bees visit the flowers for nectar or pollen. Caterpillars of the moth, Phytometra rhodarialis (Pink-Border Yellow), feed on Polygala spp. (Milkworts). Mammalian herbivores probably feed on the foliage only to a limited extent, if at all, because of its bitterness.
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Population Biology

Number of Occurrences

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Hinds (1986) reported that the species is uncommon and scattered in New Brunswick, but can be locally common in the western counties of the province. Manitoba Agriculture and Food (2000) state that it is found quite commonly throughout the southern part of their province. Voss (1985) said it is surprisingly spotty in its distribution in Michigan, although locally frequent. In a northern Illinois county, Fell (1955) reported that the species was common in two quite different situations: wooded streambanks, and low prairies. Cusick and Silberhorn (1977) considered it to be rare in unglaciated Ohio.

Medley (1993) reports that Polygala senega var. latifolia is frequent in mesic woodlands in several of the floristic regions in eastern and central Kentucky, whereas P. senega var. senega is rare in prairie patches in two of the central regions. Strausbaugh and Core (1978) stated that in West Virginia P. s. var. senega is mostly in 14 mountain counties, whereas P. s. var. latifolia had been found in just one county.

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General Ecology

Deam (1940) stated that in large old plants, the stems do branch. The species has 2 seeds in each small capsule. The seeds are reported to pop out of the capsule when ripe, during the summer (Donais 1997). Plants in Manitoba with five stems were estimated to produce 370 seeds annually (Turcotte 1997 from Elsasser 1999). Parkland Botanicals (1998) states that a mature plant can have as many as 70 stems, each with 10-40 fruits.

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Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Polygala senega

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 4
Species With Barcodes: 1
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Conservation

Conservation Status

National NatureServe Conservation Status

Canada

Rounded National Status Rank: NNR - Unranked

United States

Rounded National Status Rank: NNR - Unranked

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NatureServe Conservation Status

Rounded Global Status Rank: TNR - Not Yet Ranked

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National NatureServe Conservation Status

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N4 - Apparently Secure

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NatureServe Conservation Status

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Polygala senega is very widespread in the eastern United States and southern Canada, although unevenly distributed, and it has fairly often been reported as locally frequent or common. The species occurs in a range of habitats, some of which (e.g. mesic or dry woodlands) are widespread and plentiful. However, the ecological requirements of the species do not seem to be well understood. Also, there may be two biological entities (e.g. varieties or species) within Polygala senega as presently understood; if so, the conservation status of each taxon should be assessed independently.

The roots of Polygala senega have long been used medicinally as the product "Senega Snakeroot" (or similar names). The extent and intensity of collecting for the medicinal trade may be affecting significant populations or portions of its range, so that perhaps Polygala senega is being seriously changed genetically and in decline as a truly wild-functioning species. As well, there are a considerable number of states and provinces that have recognized vulnerability or even loss of populations within their areas of geographical expertise.

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Global Short Term Trend: Decline of 10-30%

Comments: Elsasser (1999) said that a 1958 report compiled by Manitoba's Social and Economic Research Office stated that "The digging of senega root is rarely profitable near home communities since these areas have been intensively harvested and few plants remain to be found. Persons must travel to areas where the root is abundant. Some families go by boat to the more remote areas", and the expedition's collecting could go on for days or weeks or the entire summer. The report indicated that the root was "an important source of seasonal income to some Metis and Indian families".

Manitoba Agriculture and Food (2000) state that senega snakeroot has been seriously overharvested by wildcrafters in many locations.

Elsasser (1999) of Parkland Botanicals (in Togo, Saskatchewan) says that senega roots have been commercially collected on the Canadian prairies since at least 1884, with "many tons" being gathered in 1884 to 1888 from a portion of Saskatchewan for export. He reports that the scientific research of Turcotte (1997) in Manitoba [on Hydro rights-of-way] gave mean densities of 2 plants per meter, or about 1000 plants per acre. The wild harvesters (mainly Cree and Metis peoples) tended to select larger plants and leave the smaller plants undisturbed (cf. Kenkle and Turcotte 1996). He estimates that the current Canadian wild harvest (mostly from Manitoba) is only 10-20% of historic levels, and states that in his opinion this estimated annual collection from Manitoba of 100,000 pounds of fresh roots is sustainable. [A rough approximation on the number of plants obtained can be made based on Manitoba Agriculture and Food (2000) estimates of 160 dry cultivated roots per kilogram, and two-thirds weight loss on drying, which suggests that some 2,400,000 wild roots might be obtained annually.]

Len Donais (1997) [a collector (wildcrafter) and buyer of wild plants through his company Northern Wild Harvest (of Prince Albert, Saskatchewan], states that where plants are vulnerable, like senega root in agricultural Saskatchewan, extreme care should be practiced in harvesting. In this case, he recommends that only the oldest and largest plants should be collected.

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Threats

Comments: There is evidence, acquired from reliable sources, of wild-collection of this plant for trade.

Over 90% of wild senega roots exported from Canada originates in Manitoba (Elsasser 1999; Parkland Botanicals 1998). The Saskatchewan Herb and Spice Association (2000) states that most [wild] senega presently harvested comes from Manitoba and eastern Saskatchewan (although it is not clear whether this statement is intended to apply to Canada alone or includes the United States). Manitoba Agriculture and Food (2000) state that wild populations in Manitoba and Saskatchewan are currently the major sources of supply for the North American market, and that a large tonnage is also being exported to Europe. Demand is estimated to have an annual growth rate of 5%. Because of overharvesting in past years, they state that there is a great need to cultivate the species.

Felter and Lloyd (1898-1900) mentioned that in commerce a distinction was sometimes made between Southern and Northern Senega. The former came from North Carolina, Virginia, Tennessee, Kentucky, Ohio, Indiana, Illinois, Missouri and Arkansas; the latter, with a larger root crown and root [and which they thought might be a botanical variety], was bought (since about 1871) from Minnesota and Wisconsin.

Historically over 90% of the wild senega roots exported from Canada has originated in Manitoba, which is said to also be the current situation. Elsasser (1999) of Parkland Botanicals (in Togo, Saskatchewan) reports that the export records of Canada's Dominion Bureau of Statistics for 1919 to 1957 show that root collection (as fresh weight) varied from a high of 1,820,000 pounds in 1930 to lows of 455,000 pounds in 1955 and 1923. Parkland Botanicals (1998) gives the peak year as 1931 (citing the same source), with an export of 2,000,000 pounds fresh (equals 781,000 pounds of dry roots). These records do not include domestic sales. The trade was much diminished in the 1960s-1980s because of a shift to synthetic chemical compounds.

Recent resurgence of interest in use of natural chemical compounds obtained from raw plant materials has sparked a renewal in the industrial herb trade (Elsasser 1999, Parkland Botanicals 1998). Elsasser (1999) considers the present harvests to be about 10-20% of historic levels, stating that the current annual collection of wild roots in Canada is 100,000 pounds fresh (40,000 pounds dry), with over 90% as usual from Manitoba.

The roots are utilized medicinally, after they have been removed from the knotty crown of the rootstock (Veninga and Zaricor 1976). Root extracts are considered effective for several medicinal uses (e.g. Tierra 1988) since they contain methyl salicylate (Foster and Duke 1990), glycosides, and several other drug compounds (e.g. polygalic acid, senegins, saponins) (Saskatchewan Herb and Spice Association 2000, Kako et al. 1996, Hill 1952). The Saskatchewan Herb and Spice Association (2000) states that senega is an official drug in Germany and France, and is valued for its stimulating and expectorant properties, and that the root also has an essential oil (yield 4.5%). Manitoba Agriculture and Food (2000) state that senega snakeroot is officially recognized as a medicinal herb in Canada (Health Canada-registered 'Herb and Natural Product') (cf. Briggs 1988), Germany (Commission E) and the United Kingdom (General Sales List).

The Saskatchewan Herb and Spice Association (2000) indicates that the flowers are also used [although it appears that this is only to a minor extent].

Michael McGuffin (pers. comm.) said that the American Herbal Products Association fairly recently surveyed its members regarding their trade in various species. He stated that their figures should be considered preliminary, and in general might include some double counting (if one company supplied another), resulting in over-reporting by as much as twice the actual amount. Those members who responded reported that about 600, 2000 and 6000 pounds of dried [presumably wild] roots were supplied respectively in 1990, 1991 and 1992; these might be the maximum totals and the actual totals perhaps only half the above (McGuffin pers. comm.). Although these figures might indicate their trade is going up, he considers senega snakeroot in a long-standing traditional and minor trade, but is not personally familiar with seeing it in the market.

Elsasser (1999) of Parkland Botanicals (in Togo, Saskatchewan) states the current annual harvest of wild roots in Canada to be 40,000 pounds dry weight (100,000 pounds fresh weight). He considers this about 10-20% of historic levels. He stated that most of the 1919-1957 exported production was shipped to England and the U.S., with smaller amounts sold to importers in France, Germany and Italy. Manitoba Agriculture and Food (2000) state that in 1995, most of the 10 tons of wild-harvested root product went to Japan, Europe, and the U.S.

Donais (1997) says that other species like senega root have been very hard hit by habitat loss and overgrazing in agricultural areas [his focus is Canada]. In Maine (and some other states) the species is known to have lost range and habitats to general land conversion (agriculture, urbanization).

Donais (1997) says that the species is not endangered over its entire [Canadian] range; "in parts of northern Alberta, Saskatchewan and especially Manitoba, where rocky native habitat has not been invaded by cattle or destroyed by cultivation, vast stands of senega roots can still be found". Elsasser (1999) also states that Polygala senega is distributed extensively in Manitoba [cf. Scoggan 1957], and that much of the province is rough limestone land that remains uncultivated, ungrazed, and unsuitable for forestry.

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Management

Biological Research Needs: Further study and evaluation are needed (i.e. continuation or follow-up of the work of Trauth-Nare and Naczi 1998) to determine whether the two varieties sometimes recognized in Polygala senega should be accepted as distinct biological entities (either within the species or perhaps as two species). In addition, the life history of the species seems not to be well known, including such matters as the natural age of plants, pollinators, and dispersal of the seeds.

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Relevance to Humans and Ecosystems

Benefits

Cultivation

The preference is full or partial sun, dry-mesic conditions, and soil containing loam, clay-loam, or rocky material.
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Economic Uses

Uses: MEDICINE/DRUG

Production Methods: Wild-harvested

Comments: A company with a comprehensive herbal marketing site on the internet was offering (on Dec/3/1999) to sell powdered or cut and sifted material of this species in bulk at US$ 18 per pound. Parkland Botanicals (1998) reports that in 1997 the prices reached Can$ 28,000 per clean ton of wild dry roots. Manitoba Agriculture and Food (2000) state that in 1995, the root sold for US$ 6.50-8.00 per pound. Elsasser (1999) states that in 1993 he paid the Cree and Metis peoples (who comprise at least 90% of the senega-root diggers) about US$ 3.50 per pound dry weight, with the peak price for a while in 1998 being US$ 7/lb dry.

In discussion of the family Polygalaceae worldwide in Heywood (1978), it is noted that local medicines are extracted from a few species, and that the best known is snakeroot from Polygala senega in eastern North America.

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Wikipedia

Polygala senega

Polygala senega is a species of flowering plant in the milkwort family, Polygalaceae. It is native to North America, where it is distributed in southern Canada and the central and eastern United States.[1][2] Its common names include Seneca snakeroot, senega snakeroot, senegaroot,[2] rattlesnake root, and mountain flax.[3] Its species name honors the Seneca people, a Native American group who used the plant to treat snakebite.[3]

Description[edit]

This species is a perennial herb with multiple stems up to 50 centimeters tall.[3] The stems are usually unbranched, but some old plants can have branching stems. A mature plant can have up to 70 stems growing from a hard, woody rootstock that spreads horizontally. The lance-shaped leaves are alternately arranged.[1] The lower leaves are reduced and scale-like. The inflorescence is a spike of rounded white or greenish flowers. The fruit is a capsule containing two hairy black seeds.[3] The root is twisted and conical, with a scent somewhat like wintergreen and a very pungent taste.[3] There are two root morphs; a northern morph growing in Canada and toward Minnesota has larger roots up to 15 centimeters long by 1.2 wide which are dark brown and sometimes purplish toward the top, and a southern morph found in the southeastern United States that has smaller, yellow-brown roots.[3]

The plant grows on prairies and in woods and wet shoreline and riverbank habitat. It grows in thin, rocky, usually calcareous soils. It also occurs in disturbed habitat, such as roadsides.[1]

Medicinal use[edit]

This plant had many uses among Native Americans. The Cherokee used it as an expectorant and a diuretic, and for inflammation, croup, and common cold. The Chippewa used preparations of the root to treat convulsions and bleeding wounds. The Cree chewed the root for sore throat and toothache.[4] According to Canadian botanist Frère Marie-Victorin, the Seneca may have been inspired to use the tortuous root to treat snakebite by its resemblance to the tail of a rattlesnake.[3]

The root was exported to Europe in the 1700s and was sold widely by pharmacists into the 1800s. It was marketed as a treatment for pneumonia. It is still in use as an herbal remedy. It is ground and made into patent medicines, mainly remedies for respiratory complaints.[3] It is added to cough syrups, teas, lozenges, and gargles.[5] It is toxic in large amounts, and overdose causes such symptoms as diarrhea and "violent vomiting".[3] The powdered root can be sternutatory (sneeze-inducing).[6]

The root product is called Senegae Radix,[3] Radix Senegae,[6] or simply senega.[1] Active compounds include saponins such as senegin, as well as phenolic acids, sorbitol derivatives, methyl salicylate (oil of wintergreen), and sterols.[3] The expectorant property comes from the irritation of mucous membranes by the saponins, which causes an increase in respiratory secretions and a decrease in their viscosity, giving a productive cough.[6]

Commercial trade[edit]

The root has economic value, so it is cultivated on a small scale, particularly in Japan, India, and Brazil. Until the 1960s, Canada was the largest exporter of the product, but there the root was collected from the wild. Most came from Saskatchewan and Manitoba. It is still wild-harvested today, and three quarters of the world's supply is taken from the wilds of the Interlake Region of Manitoba. Native peoples provide most of the labor, digging roots and selling them to drug companies.[3]

There is interest in turning the plant into a workable agricultural crop, especially in Canada.[3] Overexploitation of the native plant is a concern, and there has been evidence of overharvest in some areas. At its peak in the year 1931, Canada exported about 781,000 pounds of dry senega root, which equals 2 million pounds of fresh plant. More yet was supplied to the domestic market. Today about 100,000 pounds of fresh plant are harvested annually from the wild in Canada. Herbal remedies are becoming popular again, and demand for senega grows an estimated 5% per year. The biggest importers of the Canadian product, as of the mid-90s, were Europe, Japan, and the United States.[1]

The Cree and Métis people are the main collectors of the wild plant. They reportedly earned US$3.50 per pound of dry root in 1993, and up to US$7.00 per pound in 1998. A government report noted the price was US$6.50-8.00 in 1995. The dry root brought C$28,000 per ton in 1997. In 1999, one company was selling bulk powdered senega for US$18 per pound.[1]

In cultivation the plant can be propagated by seeds or cuttings. The seeds require two months of cold stratification before use. A plant takes 4 years to produce a root large enough to harvest. The roots are dug up, washed, and dried, and about 160 roots yield one kilogram of senega.[5]

Conservation[edit]

The plant is distributed widely in Canada and is not considered endangered. In some more pristine and isolated regions the species can be common. In general, it is experiencing a short-term decline of about 10 to 30%. Besides overexploitation, the plant has experienced loss of habitat to overgrazing and the conversion of land to urban and agricultural use.[1]

References[edit]

  1. ^ a b c d e f g Polygala senega. NatureServe. 2012.
  2. ^ a b Polygala senega. Germplasm Resources Information Network (GRIN).
  3. ^ a b c d e f g h i j k l m Small, E. and P. M. Catling. Polygala senega L. (Seneca Snakeroot). Canadian Medicinal Crops. Agriculture and Agri-Food Canada. 2012.
  4. ^ Polygala senega. Native American Ethnobotany. University of Michigan, Dearborn.
  5. ^ a b Senega Snakeroot. Manitoba Agriculture, Food and Rural Initiatives. Province of Manitoba.
  6. ^ a b c Radix Senegae. WHO Monographs on Selected Medicinal Plants - Volume 2. World Health Organization. 2004.
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