Echinacea is one of the most popular herbal medicines, but its popularity has come at a cost. This article shares sustainability issues around the precious medicinal echinacea species.
From local to global medicinal herb
Echinacea is a genus of flowering plants in the daisy family. The name Echinacea comes from the Greek ekhinos and means “sea urchin”, inspired by the spiky cones that hold the seeds. The genus encompasses 9 different species, of which three are well-known around the world for their medicinal use, namely E. angustifolia, E. purpurea and E. palluda. Although now world-famous, Echinacea species originally only grew in eastern and central North America, where they grow in moist to dry prairies and open wooded areas.
Echinacea species were widely used by the indigenous people of the Great Plains and the Midwest of America. The use of this plant was first recorded by Europeans during an expedition between 1804 – 1806(1). The indigenous people used the root and herb, fresh and dried for a variety of ailments, covering snake bites, infections and inflammatory conditions such as cold, flu and rheumatism. The European settlers who learned about the uses of Echinacea spp adopted its use as an ailment and by the 1880s, the herb, commonly known as Snakebite was widely known and large-scale production of Echinacea tinctures was proliferating. Fast forward to the 1990s, 100 years later and Echinacea spp are well known around the world with an ever-increasing demand. As a consequence, Echinacea spp are now being cultivated for their use (2).
In 2010 the total sales value of Echinacea products in the United States was estimated to be $10,914,500 (3). The American Herbal Product Association did a survey to record the harvest of various plant species, comparing wild harvested and cultivated sources. They list results from 23 primary raw material producers and although this may not cover all of the firms that are involved in wild harvesting and cultivation of medicinal herbs may still give an indication for the scale of harvest of E. species (4). In 2010 alone, 24 tonnes of E. angustifolia root was wild harvested, and approximately 44 tonnes were sourced from cultivation. E. purpurea is more often cultivated, and in 2010 94.4 tonnes of root from cultivated plants were sold.
The two species differ in habitat and growing requirements, which may explain the different numbers in regards to wild harvest and cultivation. E. angustifolia is at home in the prairie and prefers very well draining soils. It is drought-resistant but copes less well with too much moisture. Once germinated plants develop their first leaves and will often stay at this stage for the first growing year. E. angustifolia plants generally take a few years to mature, during which they develop a tap root that can grow 2m down into the ground. This enables plants a chance to regrow if only the first 6in have been harvested, as is often done by Echinacea harvesters. E. purpurea grows in moister woodland habitats and does not form a tap root, but spreads out instead. It is easier transplanted and easier cultivated in less dry areas of the world, which may be why it is more often grown.
Sustainability of wild echinacea harvest
Since the Europeans learned from the Native Americans about the use of Echinacea spp. as a medicinal herb, Echinacea has been harvested from the wild to be sold fresh, dried and processed into extracts. The natural habitat, the prairie, used to cover vast areas of the states, allowing big natural populations of Echinacea angustifolia. This Plants Database map from 2009 shows the natural habitat of E. angustifolia throughout the USA and Canada. The area of north-central Kansas quickly became an important area of supply, and was often valued for particular good root quality. Some families living there are now third generation Echinacea diggers, although due to constantly changing demand and prices, diggers often also have other income streams and only dig for the root if the market price is attractive enough.
Most commonly, the root is harvested using a pick mattock as a digging tool, which has been historically the tool of choice in Kansas. This method has a low impact on the land, and usually only the upper part of the root is harvested. This also allows up to 50% of harvested plants to regrow after harvest (6). Diggers also seem to be very selective in their harvest, as they only pick plants that seem to promise big taproots and are easy to dig. Other plants are left behind and areas are given 2-3 years breaks in between harvest. But as the demand for Echinacea products is ever-growing, overharvesting becomes an issue, particularly on land that is publicly owned. Cases of overharvesting and poaching have been reported in North Dakota, Montana & Missouri (6). In the past, many Echinacea spp. were treated interchangeably and sold as Echinacea angustifolia. This has added to the disappearance of the less common Echinacea spp. Populations that grow on private land are more protected by the law, and many landowners do not allow people to harvest the roots from their land. In certain areas of the country, such as Missouri, it is now prohibited by law to harvest the underground parts of wildflowers from highway rights-of-way. This law came about partially in response to Echinacea digging (5).
The low-impact harvest practice as well as the cyclical nature of the Echinacea harvest seem to allow for an overall sustainable harvest of E. angustifolia roots from the wild. The fluctuating demand for Echinacea also seems to help, as it allows for times of regeneration. And private land ownership protects Echinacea populations from being overharvested. However, Echinacea spp. still face threats to its abundance and persistence, through periodic overharvesting but also other issues. Many natural populations of various Echinacea spp, including E. angustifolia populations are declining and two Echinacea species, E. laevigata and E. tennesseensis are now considered endangered and are listed as protected species in the USA. The biggest threat seems to be the loss of their home habitats, the prairie land.
Once upon a time a third of the North American continent was covered by grasslands. French explorers named it the “prairie” which translates from French to meadow or pasture. They represent diverse ecosystems, which are very well adapted to the local weather conditions, periodic fires and droughts. There are sub-types of prairies in the States, namely the eastern tallgrass prairie, the central mixed grass prairie, and the western short grass prairie. The grasses there develop large root networks that reach deep into the ground, able to survive the harsh conditions and fires that occur periodically. The grasses and other plants form the food basis for many animals living there such as the Bison and the Prairie Dog, both of which play an important part in maintaining the local flora. Fire plays a large part in maintaining the ecosystem, as it keeps certain plant populations from growing, but encourages others and provides the soil with many readily available nutrients. Many plant seeds, including some Echinacea spp. (though not Echinacea purpurea) sprout after exposure to smoke from prairie plants, showing their adaptation to these ecosystems (7,8). But since the arrival of the European settlers, these habitats have come under threat in different ways.
Probably one of the first drastic changes to the prairie ecosystems happened between 1800 and 1890, when European settlers hunted the American Bisons to almost extinction. Historic figures of bison numbers estimate 60 million plain bison before the beginning of the 19th century, which were hunted down to one last herd in the yellowstone park by 1890. The hunt was politically encouraged to deprive the Native American population of their primal food source as the Europeans colonised North America. The prairie dog numbers also suffered greatly, reducing by 98% (9). Both of these species are considered cornerstone species for the prairie habitat and their loss is contributing to the loss of prairie habitats (9).
Fire plays an important part in regenerating prairie habitats, but through overgrazing in the late 19th century by cattle and sheep, the fire frequency was reduced, adding to the many changes in this environment, which was even more encouraged from the 1950s onwards, when fire suppression programs were started, that altered ecological processes, which increased non-native species invasion and promoted less fire tolerant species (8).
The picture below shows a patch of mixed grass prairie at Kirwin NWR in Northcentral Kansas. It was burned a couple months previously but already shows a flourishing flora, including Echinacea angustifolia and Catclaw Sensitive Briar (Mimosa nuttallii).
Today it is estimated that there has been a 99% loss in tallgrass prairie, and a 75% reduction in shortgrass prairie. The loss of cornerstone species and the reduction of fires play a big part. But most likely the biggest is the conversion from wild prairie land into agricultural land, which is still happening today. According to World Wildlife Fund’s (WWF) 2021 Plowprint Report about 2.6 million acres of intact grassland – an area larger than Yellowstone National Park – were ploughed up in 2019 to make room for row-crop production. The largest portion of grasslands in this region was replaced by wheat, representing 42% of newly ploughed land, followed by corn (10%) and soy (10%) (10). Herbicide use is also a common practice in modern world farming and landscape management, which has also been found to affect local Echinacea populations (5).
These impacts, when combined with harvesting pressure, climate instability and further land changes, may threaten the species long-term survivability, as indeed some Echinacea species are threatened with extinction today.
Growing echinacea commercially can be very challenging, particularly with E. angustifolia. Prices fluctuate and plants take at least three years to grow. E. purpurea seems to grow more easily in cultivation, however is less preferred by some. In Kansas, where people have been harvesting Echinacea for generations, it has generally encouraged a positive relationship between the people and the land, and sustained Echinacea populations over the last 120 years. Some landowners have changed from their use of herbicides to controlling brush manually, to support their Echinacea populations (5). And the wild harvest of Echinacea may even benefit the whole prairie habitat as well as other species if it means people start looking after these better, to protect their local Echinacea stands. Wild harvesting can easily get a bad reputation, however if done correctly & in relationship with the land, it can be far more sustainable than any cultivated crop. Prairie land is an essential ecosystem for many species, including Echinacea spp. If we want to sustain the natural occurring Echinacea populations, without the use of pesticides, herbicides and other detrimental tools, we need to not only think about sustainable harvest rates but consider all the various impacts humans have on the whole prairie ecosystem.
References
- Rogers D. H. 2009.Echinacea angustifolia D.C. Blacksamson echinacea. Smithsonian National Museum of Natural History.
- https://www.friendsofeloisebutler.org/pdfdocs/echinacea_angustifolia.pdf
- Binns S. E., Baum B. R., Arnason J. T. 2002. A Taxonomic Revision of Echinacea (Asteraceae: Heliantheae). Systematic Botany, Vol. 27, No. 3 (Jul. – Sep., 2002), pp. 610-632.
- Blumenthal, M., A. Lindstrom, C. Ooyetn, and M. Lynch. 2012. Herb Supplement Sales Increase 4.5% in 2011. HerbalGram 95: 60.64.
- American Herbal Products Association. 2012. Tonnage Surveys of Select North American Wild-Harvested Plants, 2006–2010. Silver Spring (MD).
- Kindscher, K. 2016. Echinacea – Herbal Medicine with a Wild History. Kansas Biological Survey. University of Kansas.
- Hurlburt, D. P. 1999. Population ecology and economic botany of Echinacea angustifolia, a native prairie medicinal plant. Dissertation, University of Kansas,
- Lawrence.
- Chen, Y. 2014. The Effect of Smoke on Seed Germination: Global Patterns and Regional Prospects for the Southern High Plains.
- Forsberg, B., Jefferson, L., Havens, K. Effects of Smoke on Prairie Seed Germination. Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, IL 60022.
- Sampson, F., Knopf, F. 1994. Prairie conservation in North America. Other Publications in Wildlife Management. 41.
- WWF Plowprint 2021. https://www.worldwildlife.org/publications/2021-plowprint-report, accessed 28/06/2023