Siberian Elm Monograph


Siberian Elm

(Ulmus Pumila)

Family: Ulmaceae


Taste: Mucilaginous, bland, sweet

Tissue State: Dry

Degree of Action: 1st and 2nd

Properties: Demulcent, emollient, nutritive, expectorant, anti-inflammatory, immune-modulating through the gut-associated lymph tissue, anti-microbial, antioxidant, mildly astringent

Key Uses: Topically and internally for dryness, irritation, inflammation, and infection, especially of the GI tract, skin and lungs. Constipation, diarrhea, nausea, ulcers, dry coughs, allergies, edema from fluid imbalance originating in dryness, as a drawing poultice, and moisturizer.  Potential for immune modulation as a result of systemic inflammation, dysbiosis, or auto immune diseases.

Part Used: inner bark

Dosage: standard cold infusion, to 1 quart daily.  porridge/gruel 1-4g/0.4-1pt water, bring to just below boil.  Topically as needed, as dry powder for drawing, moist when desired.

Constituents: polysaccharides, phenolics, steroids, terpenoids, glycosides, flavonoids, peptides, and organic acids (You, 2013)


Botanical Characteristics: 

Tree to shrub, depending on moisture.  Up to 70’ tall and 50’ wide.  Rough grey-brown fissured bark.  Zig zag alternate leaf attachment to grey twigs with a leaf bud at each end and scattered lenticels.  Leaves light bright green in spring, turning to deeper green on top, staying pale on bottom, long, tapered at each end, and simply serrate. Small purple buds early spring, then 2 to 5 small green drooping flowers per bunch February through April, before the leaves. Samara fruit with single seed April and May.  (Wright, 2016)


Spring is coming, 

I see the tiny purple buds, 

peering up soft grey fissures, 

and squinting into the sun.

The sap is moving, 

bark harvest time.


Siberian elm is native to the Eastern Steppe and Gobi Desert.  It is the only species of tree that grows in some parts of the Gobi, where it grows on south facing slopes, in dry drainages, impervious to alkaline and salty soils. Small clumps of gnarled bent trees, in full sun, face the wind.  

The pollen travels this wind, this openness, sometimes up to 8km.  Connection.  Diversification.  

The seeds appear in spring, sometimes before the leaves.  Samaras.  Light green, flat, papery discs, filled with chlorophyll, photosynthesizing.  A favorite food of many animals of the area, they are produced prolifically to overcome the odds. 

Ulmus pulmila is a survivor from a harsh place.  Skilled in adaptation.  In drought they can cut off water supply to parts of their canopy, and can even die back to the root crown, regrowing when water allows.  Roots spread both deep and wide.  Seeds only sprout where there’s plenty of light.  And saplings grow quickly.  A tree that grows fast and well where most trees won’t grow.  

That hardiness, perseverance, and adaptability were what brought Siberian elm to New Mexico.  

Siberian elm first came to the U.S. in 1905.   Seeds and cuttings were collected from the Temple of Pekin and grown out by the UC Berkeley Forest Nursery in California.  Nurseries everywhere started growing them, praising their toughness, and fast growth.  And they sold.  

The farmers in the great plains had tilled up the prairie and the dust bowl was beginning.  Siberian elm became the most planted street and shelter belt tree in the midwest, holding, collecting the soil.  They were also planted as street trees in eastern towns, where other species of elm were dying from dutch elm disease.  And in New Mexico, they became the next in a series of fads in tree planting to bring a canopy and wind block to towns where trees didn’t always want to grow, or stay alive.  In Albuquerque, Tingley was handing out seeds.

Governor of New Mexico, then mayor of Albuquerque, Clyde Tingley loved Siberian elm.  The towns of New Mexico had been planted primarily with cottonwoods that were dying from lowered water tables, and black locusts, which were being attacked by borers.  With the dust blowing in from the east, and the dust bowl migrants following the wind, Tingley found hope in Ulmus pumila.  With New Deal money, he distributed seeds and saplings statewide to anyone who would plant them.  From the 1930’s through the 1950’s Siberian elm was the tree of choice planted in New Mexico towns and cities.  

Each spring in Albuquerque, the samara season, when the paper seeds cover everything, ready to sprout in cracks, newly tilled dirt, anywhere they can find, they are called Tingley Snow….or dandruff, flakes, chips.  And usually they are cursed.

Siberian elm is now listed as a noxious weed across the state.  The same resiliency and adaptation that makes Siberian elm a survivor, makes it uncontrollable and invasive.  Coming up where it’s not wanted.  Coming back when it’s cut down.  New sprouts and shoots emerging every year in the forgotten spaces and gardens alike.  Roots burst sewer pipes.  Limbs fall on roofs.  Fields grow up into single species forests.  Sidewalks crack.  Siberian elm does not behave.  Or it behaves exactly as it should.  

Santa Fe Parks and Recreation Department has spent more money for the last 10 years trying to eradicate Siberian elm than any other plant without seeing any change in the elm population of the city.  Plumbers in the older parts of town, pre-dating plastic pipes, are constantly called to fix pipes that Siberian elm roots have found their way into.  If you stop most anyone on the street, they will have either learned that Siberian elms are bad, or have personal stories of dislike and misfortune.  This same story is played out in many towns across the state (Citters, 2018).  

The hatred of this tree is why Ben Wright started studying Ulmus pumila.  Ben, an arborist from Taos, NM, is studying Siberian elm for his masters and digging deeper into the plant-human relationship between us.  In his hometown, Siberian elm makes up 30% of the city canopy.  

“There are some places where the streets are lined with Siberian elm, and that is what is providing shade, so removing it is out of the question, not only because it is difficult, but because it is providing benefits.  You may think you don’t need it, but what nature and trees add to our lives is beyond comprehension,”  

Wright told the Santa Fe New Mexican newspaper (Moss, 2017).

Ulmus pumila, who was planted during a climate change event, a time when we allied with this tree to create tiny canopied oases in the dust storm, may be our ally again as we move into this new epoch of rapid and intense climate change.  

A 2019 simulation from Los Alamos Laboratories projects, “widespread mortality of needleleaf evergreen trees within southwest USA by 2100.”  Their models show this tree death being linked to rising temperatures, which will increase the severity of the effects of drought on trees.  They believe it will effect warmer southern New Mexico conifer forests first and more intensely, but see massive conifer death across the whole state as a likely possibility (McDowell, 2019).  

Siberian elm is a good candidate for survival through times of death and change.  Wright and colleagues wonder why we are trying to kill off one of the only trees that may survive.  And not only survive, but possible help ease the severity.  

The wide leaves and rapid transpiration of Siberian elm release more water into the atmosphere than prairies or scrub ecosystems.  And this vapor changes local rainfall patterns.  Calls the rain.  Trees bring rain.  

How can we survive with Siberian elm in the anthropocene, this time of human influenced change?  What can we learn from this tree that thrives in and in this thriving can crack and destroy our human made streets and sewer systems, and can overwhelm human changed ecosystems like farm fields tilled and rivers diverted.  How do we change together? 

I live outside of Las Vegas, New Mexico, on the other side of the mountain from Santa Fe.  It’s a town on the edge of the prairie.  The edge of the Sangre de Cristo Mountains flattens out into rolling open hills, moving east.   

Planted Siberian elms have made a home here.  Lining streets, coming up from sidewalk cracks, mixed with cottonwoods along the river fields.  Stumps with new shoots emerging are a common sight.  Trimming and thinning are always desired.  

My partner and I work with the local garden club to find people who need some cutting done.  We don’t take it all, but instead try to find a balance between human and elm desire.  They get some yard work.  We get some bark and wood.  We come home, sort, and strip the bark.  

The Ulmus genus contains around 30 or 40 species.  I’m not just being vague, there is contention around those numbers.  Elms can hybridize with each other.  Pteleologists, botanists that study elms, seem to use words like forms and intermediates along with species (Watson, 1997).  

Slippery elm (Ulmus rubra) is the elm you have most likely heard of from herbal commerce, but other elms are used medicinally as well.  Although I’m having a hard time finding information on all of the different species, I’m guessing that at least most of them have local medicinal uses where they grow. 

 A few examples: 

Linaeus didn’t differentiate between species in his 1794 Materia Medica, but instead included the entire Ulmus genus as astringent and vulnerary and indicated for ascites (Upton, 2011).  

In A Modern Herbal, Maude Grieves lists the actions of Ulmus campestris as, “Tonic, demulcent, astringent and diuretic (Grieves, 1931).”  

The Muscogee Nation uses Ulmus americana for toothaches, broken bones and regulating bowel movements (Jordan, 2002).

Very early in my herbal education, I learned to substitute mallows for slippery elm bark. Slippery elm trees didn’t grow in the west where I lived, and I was taught and practice bioregional herbalism whenever possible.  Slippery elms are dying of dutch elm disease, I learned.  Slippery elm is over harvested, I heard.  And yet, the few times I tried slippery elm bark I new it was different.  The slight nourishing warmth, the mucilage had a different taste, sweeter, a different kind of fullness than marshmallow or Malva neglecta.  I new it wasn’t a direct analog.  A good substitute for sure, but there were differences.

“Slippery elm inner bark is the 4th largest harvested commodity in the herbal market, according to the American Herbal Products Association (AHPA)…It can be estimated that 4,000-19,000 trees were harvested annually to meet the demand for 2004-2007 (Upton, 2011).”

Dutch elm disease (DED), a fungal infection, has been killing elm trees in the U.S. since around 1930, just as Siberian elm was getting popular as a tree to plant.  American elm (Ulmus americana) seems to be the most susceptible to the disease, spread by bark beetles, but slippery elm is also susceptible.  There are many projects aimed at DED resistance in native elm trees, and they are being grown and replanted.

The DED resistant trees however, have no resistance to elm yellows, a bacterial disease that effects the phloem, where DED effects the xylem (Martin, 2012).

Siberian elm is resistant to dutch elm disease and elm yellows.  It does get other diseases like wetwood, aka slimeflux, a bacterial disease that causes a sour smelling fluid to seep from the trunk, especially in crotches.  Most of the diseases and infestations common in siberian elm are not deadly.

I started working with Siberian elm when I moved to New Mexico five years ago.  Being surrounded by these beautiful, tenacious survivors, I wondered.  How do these elms compare medicinally to slippery elm?  How are they different?  What can our relationship be? And I started learning, listening, experiencing.

First, when the light green samaras started to fall, I ate some.  And they were delicious.  Ulmus plumilla fruits are high in flavonoids, especially kaempferol glycosides and quercetin.  A 2019 study from China says, 

“The content of kaempferol glycosides was 787 mg 100g-1 DW in U. pumila, which constituted approximately 64% of its total flavonoid content. In recent years, studies have reported kaempferol as a valuable functional secondary metabolite with a broad range of therapeutic applications because of its anti-cancer, anti-metastasis, antioxidant, hepatoprotective and neuroprotective effects. Therefore, the fruits of U. pumila were potential functional foods (Feng, 2019).”

The quercetin content may also be beneficial for its mast cell stabilizing capabilities, especially since the samaras are fresh and ready in April and May when a lot of common allergens are starting to fly.

 You can eat the samaras raw as a snack, collect a lot and make a salad, or make a dish from northern China called Yu chian zi (elm coin) by mixing the fresh samaras with flour, steaming them and seasoning with salt, sesame oil, onions and garlic (Hu, 2005).  

Erica Davis, of Colorado, made a delicious looking shaved carrot and Siberian elm samara salad with a creamy horseradish dill and garlic dressing (Davis, 2016).

After eating my fill of samaras, I started experimenting with the bark.  As a cold infusion, it seems just as mucilaginous as slippery elm.  I’ve found that, when I stuff some long strip of it into a quart jar and fill with cold water, as long as I keep it cool enough (in the fridge in the summer and in a cool room in the winter) I can keep adding water for up to 2 weeks and get layer after layer of mucilage without it spoiling or running out of goop.

I am excited to try this method of preparation with siberian elm: 

“A mucilage of elm of good quality should be prepared with very cold water. Take shredded elm bark, bundle the shreds together after the manner of making a whisk broom, by tying one end with a long string. Suspend the bundle of bark in a vessel of ice water, from a support placed across the top of the container. A thick, ropy, mucilaginous preparation will result which is far more serviceable than those prepared on a water bath, the common method of preparing mucilage of elm (Felter, 1922).

I have been using the cold infusion of slippery elm bark both internally and topically.  Topically I have found it to be a lovely demulcent for both hair and skin.  It makes a wonderful addition as the “waters” to lotions, and after reading about how Kiva Rose, from southwestern New Mexico, has found it to work well in an oil, would love to try it in both the “waters” and “oils” parts (Rose, 2019).  

I use Siberian elm as a face and whole body moisturizer with dry skin and dry people.  It’s also gently soothing and works well for irritated dry tissues, like around the nostrils after lots of nose blowing, or in combination with something like licorice root for eczema.  I also love it as a hair treatment, either drenching my hair in the cold infusion, leaving it for a few hours, then rinsing, or applying in smaller amounts as a leave in conditioner, or daily rejuvenating spritz.  

Internal and external combo, with a couple cups a day of cold infusion added to the external application, I have found to be key for naturally dry people who live in dry places.  

A Modernal Herbal includes an intriguing topical use for Ulmus campestris galls,

“In Persia, Italy and the south of France, galls, sometimes the size of a fist, are frequently produced on the leaves. They contain a clear water called eau d'orme, which is sweet and viscid, and has been recommended to wash wounds, contusions and sore eyes. Culpepper tells us: 'the water that is found in the bladders on the leaves of the elm-tree is very effectual to cleanse the skin and make it fair.’ (Grieves, 1931).”

Some of the ways I use Siberian elm come from me trying it as a mallow substitute.  Yerba de la Negrita (Spheralcea coccinea) is a common and traditional hair conditioning treatment where I live and I’ve drank whichever mallow is around and plentiful (usually Malva neglecta) to survive the dry climate for years.  They all work well for their demulcent properties and I do switch back and forth.  In detail, I find Siberian elm to be more mucilaginous than the mallows, with a touch of astringency, and a little more of a nutritive feel.  The mallows tend to be more cooling and impart a different quality of soothing.  

Siberian elm is used in Traditional Chinese Medicine for edema, mastitis, gastric cancer, and inflammation (Wang, 2004).  It is used to treat infections in Korea and throughout its native range is traditionally used for abscess, infection, edema, rhinitis, empyema, and otitis media, gastric and duodenal ulcers, and gastric cancers (You, 2013).

Slippery elm has a somewhat similar history of medicinal uses.  John Uri Lloyd gives a synopsis in The History of the Vegetable Drugs of the U.S.P.,

"The Indians and settlers of North America valued the inner bark of [slippery elm] as a poultice; in certain skin diseases they used it as an external application, and as a soothing drink in fevers. In bowel affections they employed a cold decoction. Schopf, 1787, refers to it as "salve bark." An infusion made by digesting the shredded inner bark of slippery elm in cold water, has (after the teaching of the Indians) ever maintained a high reputation in domestic North American medication in fevers, and especially in diarrheas connected therewith. The mucilaginous qualities render the powdered bark peculiarly adapted to the making of poultices, in which direction it was known to all the early settlers of America and was by them introduced to the medical profession (Lloyd, 1911).”

(Lloyd's use of the generic term Indians, in place of specifying which and specifically who this information is coming from is common practice in writing of this era.  Use of indigenous knowledge without proper credit or permission, and often for profit by settlers was and still is a common practice.  How can we change this practice?)

Siberian elm has more recently, been pigeon holed as a demulcent.  The American Pharmacopoeia and Therapeutic Compendium has a thorough write-up on slippery elm.  They give this opinion on current use,

“Slippery elm is one of the few botanicals approved in the US for medicinal use, as an oral demulcent ingredient in over-the-counter (OTC) products, such as lozenges. Such indication is congruent with the historical use of slippery elm, while at the same time being very limiting when compared with the broad spectrum of therapeutic uses for which this plant had been successfully utilized in the past.”

They go on to suggest some other mechanisms and actions that we may be overlooking,

“The mechanical effect of locally coating irritated mucosa with the viscous hydrocolloidal fiber from slippery elm has traditionally been viewed as the primary means by which slippery elm, or its aqueous extracts, exert their therapeutic activity. However, there is also indirect evidence to suggest that the putative effects of slippery elm may involve mediation by gut-associated lymphoid tissue (e.g., Peyer’s patches). Additionally, there has been some investigation of the anti-oxidant constituents of slippery elm that may contribute to its widely reported anti-inflammatory and vulnerary effects on the bowel mucosa (Upton, 2011).”

Studies on siberian elm have found it to have immunomodulating, antioxidant, anti-inflammatory,  antimicrobial, cytotoxic, and adipogenisis inhibiting effects.  The traditional uses and studies of both siberian elm and slippery elm seem to point to similar medicinal actions.  I feel confident using siberian elm as an analog for slippery elm in my practice, and would be excited if practitioners in its introduced areas would do the same.  

The only writing I can find on current use of siberian elm in western herbalism comes from my neighbors in New Mexico and Colorado.  Briana Rose Wiles works with Siberian elm as an analog for slippery elm.  She uses the bark powder for constipation and diarrhea, ulcers, GI inflammation and intestinal permeability, nausea, and dry coughs (Wiles, 2018).  And Dara Saville uses Siberian elm as an, “anti-parasitic, anti-fungal, antilithic, expectorant, and demulcent (Saville, 2016).”


Following is a short review of the studies on Siberian elm.

A 2014 study from South Korea looked at the anti-inflammatory effects of Siberian elm bark by looking at total phenolic content, radical scavenging activity, effects on RAW264.7 cells stimulated with inflammatory Lipopolysaccharide (LPS) treatments, and which constituents may be participating in its anti-inflammatory effects.  They found that all preparations, including a crude water preparation, had anti-inflammatory, nitrous oxide inhibitory effects, and that the ethyl acetate was the most effective. They isolated Icariside E4 from the ethyl acetate extraction for further study.  

“The findings of the present study clearly provide evidence that supports the traditional use of stem bark of U. pumila in the treatment of inflammatory diseases. Further studies in relation to anti-inflammatory potential of the isolated compound icariside E4 are under progress (Joo, 2014).”

A 2013 study from South Korea looked at the antibacterial properties of siberian elm, particularly its effectiveness against different strains of antibiotic resistant bacteria (MRSA).  This study took place in petri dishes, so the information is relevant to anywhere siberian elm can be applied directly, and may or may not cary over to systemic effects.  This study is also working to provide evidence for traditional medicinal uses of siberian elm,

“U. pumila ethanol extract showed antibacterial abilities against all the strains, 12 strains of MRSA isolated clinically and 1 standard strain of MRSA. The fact that U. pumila extract suppresses growth of S. aureus could provide the scientific basis, that the extract had been used for the treatment of infectious diseases (You, 2013).”

A 2015 study from South Korea chose to study Siberian elm for its effects on adipocytes because of its triterpenoid content.  They looked at the effects of a methanol extraction on  adipocyte proliferation, differentiation and cell cycle progression in 3T3-L1 cells.  They state, 

“Though it was once believed that the number of fat cells does not increase during the entire life of individual, evidences now have shown that the number of fat cells can increase or decrease depending individual’s physiological condition (Gregoire

et al., 1998), hence, targeting the life cycle of adipogenic cells becomes a viable approach in controlling obesity and its related problems. The data above represents that [Ulmus pumila] extract containing triterpenoids not only significantly affect the viability of preadipocytes by causing G1 cell cycle arrest, but also influence adipocyte differentiation and lipid accumulation in 3T3-L1 fibroblastic cell line. [Ulmus pumila] extract significantly down regulated cell proliferation in a dose and time dependent manner. The results showed for the first time that [Ulmus pumila] profoundly inhibited progression of adipocytes to S phase and further identified that [Ulmus pumila] treatment causes a G1 cell cycle arrest (Ghosh, 2015).”

A 2004 study from Japan looked at the cytotoxic effect of two constituents of Siberian elm, Mansonone E and F (ME and MF) on human cancer cells.  They found,

“ME, an active component of U. pumila promotes tumor cell death by modulating the balance of Bcl-2 family proteins and signals to apoptotic effector molecules (caspases), which subsequently cleave key cellular proteins to generate the apoptotic morphology. But the antiproliferative activity of ME cannot be entirely blocked by caspase inhibitors; therefore other pathways might participate in inducing apoptosis in human tumor cells. The mechanism of tumor cell apoptosis induced by ME remains to be further elucidated (Wang, 2004).”

I find it interesting that some of the constituents being studied are not very water soluble.  The focus in western herbalism is on the mucilaginous effects of slippery elm, and because of this, often its cold water soluble constituents may be missing out on some of its antimicrobial, antioxidant, immunomodulating and cytotoxic effects.  I’m curious about experimenting with alcohol extracts of slippery elm, even though the mucilaginous components won’t extract well, and I will definitely be using the whole powder in practice much more frequently than I have previously.  

Where I live, we have  complicated relationships with Siberian elm.  I hope this monograph has successfully dug into some of the crevices of the details.  My friend Geneva has Siberian elms lining her driveway, and I often think of her words when people start talking about how much they hate Ulmus pumila.  “Before I think about taking a plant away from my farm,” she told me, “I make sure I have already replaced its role in the ecosystem with another plant.”  Siberian elms are allies of mine, and I hope they see me as a friend.  I look forward to continuing and deepening our relationship.


References

Photo 1: Max Licher.  retrieved from: http://swbiodiversity.org/seinet/taxa/index.php?taxon=Ulmus+pumila 

Photo 2: Ben Wright.  retrieved from: https://www.taosnews.com/stories/ever-wondered-what-siberian-elms-are-doing-in-new-mexico,25337 

Wright, J (2016) Ulmus pumila.  Term paper.  Oregon State University.  retrieved from: http://www.emnrd.state.nm.us/SFD/treepublic/documents/Wright2016Ulmuspumila-Siberianelm.pdf 

Citters, K (2018) a brief history of urban trees in New Mexico.  retrieved from: https://groundworkstudionm.com/wp-content/uploads/2019/06/A-Brief-History-of-Urban-Trees-in-NM.pdf 

Moss, R (2017) Rethinking the dreaded Siberian elm.  Santa Fe New Mexican.  retrieved from: https://www.santafenewmexican.com/news/local_news/rethinking-the-dreaded-siberian-elm/article_60654cca-f0a3-565a-8909-e36cd7e8d6a6.html

McDowell, NG (2019) Multi-scale predictions of massive conifer die-off due to chronic temperature rise.  retrieved from: https://www.osti.gov/pages/servlets/purl/1492529 

Watson, W (1997) Elms in Worcester.  Worcestire Record number 3.  retrieved from: http://www.wbrc.org.uk/WorcRecd/Vol1Iss3/elms.htm 

Upton, R (2011) Slippery Elm Inner Bark, Ulmus rubra.  American Herbal Pharmaopeia and Therapeutic Compendium.  Scotts Valley, CA.  retrieved from: https://epi4dogs.com/wp-content/uploads/2017/11/AHP-Slippery-Elm.pdf 

Grieves, M (1931) A Modern Herbal.  retrieved from: https://botanical.com/botanical/mgmh/e/elmcom08.html 

Ann Jordan and Lewis, David Jr (2002). Creek Indian Medicine Ways: the enduringpower of Mvskoke religion. University of New Mexico Press, Albuquerque.

Martin, D (2012).  Pest Alert, Elm Yellows.  US DOA FS Northeastern Area State and Private Forestry.  retrieved from: https://www.fs.usda.gov/naspf/sites/default/files/publications/elm_yellows-pest-alert-120709_low-res.pdf 

Hu, S (2005) Food Plants of China.  The Chinese University of Hong Kong.  retrieved from: https://books.google.com/books?id=2OiYydyrsygC&pg=PA354&lpg=PA354&dq=Yu+Bai+Pai+Ulmus+pumila&source=bl&ots=lUSruN-y_u&sig=ACfU3U0vdVF3BhjfZq_xLKl9x5ttJLdOMQ&hl=en&sa=X&ved=2ahUKEwiTj4imrcTkAhXuc98KHd9TDq8Q6AEwC3oECAoQAQ#v=onepage&q=Yu%20Bai%20Pai%20Ulmus%20pumila&f=false 

Davis, E (2016) Elm Samaras are Edible, Gourmet.  Wild Food Girl, Foraging the Wild for Plants and Stuff to Eat.  retrieved from: https://wildfoodgirl.com/2016/elm-samaras-edible-gourmet/ 

Felter, W (1922) The Eclectic Materia Medica, Pharmacology and Therapeutics.  retrieved from: https://www.henriettes-herb.com/eclectic/felter/ulmus.html 

Rose, K (2019) Wychwood: The Earthen Healing of the Elm.  retrieved from: https://enchantersgreen.com/blog/wychwood 

Gu, Z., Feng, C., Li, S., Yin, D., Wu, Q., Zhang, L., & Wang, L. (2019). Identification of flavonoids and chlorogenic acids in elm fruits from the genus Ulmus and their antioxidant activity. Journal of Separation Science. doi:10.1002/jssc.201900302.  retrieved from: https://sci-hub.se/10.1002/jssc.201900302 

Uri Lloyd, J (1911) The History of the Vegetable Drugs of the U.S.P.  retrieved from: https://www.henriettes-herb.com/eclectic/lloyd-hist/ulmus.html 

Wiles, B (2018) Mountain States Medicinal Plants: Identify, Harvest and Use 100 plants for Health and Wellness.  Timber Press.  Portland, OR.  retrieved from: https://books.google.com/books?id=GVpeDgAAQBAJ&dq=Ulmus+pumila+medicinal+uses&source=gbs_navlinks_s 

Saville, D (2016) Aligning with Invasive Trees as Herbal Medicine.  retrieved from: https://albuquerqueherbalism.com/2016/12/27/aligning-with-invasive-trees-as-herbal-medicine/ 

Joo, T et. al. (2014) Inhibition of nitric oxide production in LPS-stimulated RAW 264.7 cells by stem bark of Ulmus pumila L..  Saudi Journal of Biological Sciences, 2014 Nov; 21(5): 427–435.  Published online 2014 May 5. doi: 10.1016/j.sjbs.2014.04.003.  retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191610/ 

You, Y et. al. (2013) Ethanol Extract of Ulmus pumila Root Bark Inhibits Clinically Isolated Antibiotic-Resistant Bacteria.  Evidence Based Complementary and Alternative Medicine.  Published online 2013 Oct 8. doi: 10.1155/2013/269874.  retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817893/ 

Ghosh, C., Chung, H.-Y., Nandre, R. M., Lee, J. H., Jeon, T.-I., Kim, I.-S., … Hwang, S.-G. (2012). An active extract of Ulmus pumila inhibits adipogenesis through regulation of cell cycle progression in 3T3-L1 cells. Food and Chemical Toxicology, 50(6), 2009–2015. doi:10.1016/j.fct.2012.03.056.  retrieved from: https://sci-hub.se/10.1016/j.fct.2012.03.056 

Wang, D., Xia, M., Cui, Z., Tashiro, S., Onodera, S., & Ikejima, T. (2004). Cytotoxic Effects of Mansonone E and F Isolated from Ulmus pumila. Biological & Pharmaceutical Bulletin, 27(7), 1025–1030. doi:10.1248/bpb.27.1025.  retrieved from: https://sci-hub.se/https://doi.org/10.1248/bpb.27.1025