Purple Loosestrife: a misunderstood medicinal

by Ruthie Kolle Hayes

 

Latin: Lythrum salicaria

Family: Lythraceae (the loosestrife family)

Folk names: spiked loosestrife, purple lythrum, flowering or blooming Sally, purple willow herb, salicaire, rainbow weed, bouquet violet, purple spiked willowstrife

Energetics: cool, dry, moist

Properties: astringent, demulcent, antibacterial, styptic, vulnerary, febrifuge, antiamoebic, anti-inflammatory, antihistamine, antispasmodic, anti-hemorrhagic

Taste: sour, cooling, sweet

Degree: 3rd

Tissue state: heat, damp, relaxation

Key uses: gastroenteritis, dysentery, staunching blood flow
 

History, Folklore & Traditional Use

Even though they are in two separate botanical families, purple loosestrife got its name for its similar insect-repelling actions to that of yellow loosestrife.  Farmers used to hang the plants around the yokes of their oxen and workhorses to keep biting insects from agitating their animals.  Traditionally, the leaves were used as a vulnerary to stop active bleeding either as a poultice or taken as a tea. 

The name “lythrum” comes from the Greek “lythron” which loosely translated, means “bloody gore” and could be a reference to the flowers being used as a natural red dye or the color the leaves turn in autumn.  According to Dr. Lindley’s Flora Medica (1838), purple loosestrife was used as a hide-tanning agent, owing to its astringent properties. 

The plant also has a history of being used for gastroenteritis, dysentery, ulcers, liver problems, fevers, constipation, and typhus- a sometimes fatal bacterial infection that causes flu-like symptoms, rash, and brain inflammation.  An infusion of the herb was gargled and swished for sores in the mouth and throat.  Culpeper preferred purple loosestrife over eyebright for treating the eyes.  He claimed that it “...cleanses and heals all foul ulcers whatsoever, by washing them with the water, or laying on them a green leaf or two in summer, or dry leaves in winter. This water, when warmed and used as a gargle, or even drunk sometimes, cures the quinsy, or king’s evil of the throat (peritonsillar abscess). The said water applied warm takes away spots, marks and scabs in the skin; and a little of it drunk, quenches extraordinary thirst.” 

“A Supplement to the Pharmacopeia and Treatise on Pharmacology in General” (London, 1828) cites its uses as an “ophthalmic, astringent, used in the winter diarrheas of northern countries, also as tea and to make beer.”  It is said that purple loosestrife seeds came to New York in the sandy ballast of a cargo ship in the 1800s. 
 

Botany & Ecology

Purple loosestrife was originally planted as an ornamental for its showy purple flower spikes and hardy, clumping habit.  This herbaceous perennial quickly escaped garden cultivation and can now be found growing in wetter soils where water meets land such as margins of lakes, soggy drainage ditches, marshy areas, fens, floodplains, bogs, wetlands, and disturbed areas left to go wild again (which is where I met this plant for the first time).  It can also tolerate drier growing conditions, but in a wet, sunny, open meadow it can form large drifts or stands, becoming a monocrop.  It is now listed as a highly invasive plant in much of the eastern US.  Some states even go so far as to make it illegal to plant, sell, or even possess purple loosestrife. 

It can now be found in most of Canada and all of the United States, save for a few of the southernmost states.  Despite being vilified, this plant does have its champions in the scientific world who beg us to reconsider our feelings towards it and the cost of eradicating it, both environmental and financial.  A 2009 paper by Claude Lavoie takes a hard look at our preconceived notions of purple loosestrife.  In the same vein, this paper argues that the plant is not the bully we are made to believe it is, and that the biological control methods being implemented to control it could potentially cause more harm in the long run. 

Studies are also being done on purple loosestrife’s ability to filter and remove toxins from the environments in which it grows.  One study even demonstrated its ability to tolerate high lead levels in a polluted habitat.

The plant propagates by a creeping rhizome to create clonal colonies and also freely self-seeds.  A single plant can create 2.7 million seeds in one year!  The stems are square (sometimes 5 or 6 sided) with alternating, whorled, and opposite lanceolate leaves that are covered in fine hairs.  The long slender stems are topped with striking flower spikes which are packed with 6-petaled pinkish purple flowers.  There are 3 different types of flowers among purple loosestrife plants.  Each plant only has one type, but needs one of the other two types to pollinate.  The central stem of the plant grows to around six feet tall, with branching stems that curve inward.
 

Clinical Use

Purple loosestrife is a lesser-known medicinal, probably because it’s mainly thought of in a negative context as an invasive plant.  It has actions as both an astringent and a mucilant, making it appropriate for conditions where tone and moisture need to be restored to tissue.  Herbalist jim mcdonald states that adding more leaves and stems to the medicine brings forth the astringent qualities, while more flowering tops highlight the moistening actions.  This makes purple loosestrife appropriate for addressing the symptoms of “...diarrhea, bacterial or amoebic dysentery, enteritis, IBS, leaky gut, and as a gargle for sore throats.” (David Winston).  He also goes on to note that it’s helpful as a “douche for leucorrhea and bacterial vaginosis, and as a nasal douche for nose bleed...the stems are chewed on to help treat swollen, red, bleeding gums caused by pyorrhea and gingivitis.” 

Henriette Kress also sings its praises, naming it “one of the most valuable of all vegetable astringents yet known to man. In its action it differs from other astringents generally in promoting instead of suppressing the secretive powers of the mucous surfaces, and leaving them moist and invigorated.”  Purple loosestrife has been successfully used in Switzerland, Boulogne, and Lyon to quell dysentery outbreaks and in cholera outbreaks in England in the 1800s.  It is currently used in Europe as a wash for dry, red, irritated eyes and ophthalmic ulcers.  Sufferers of sinusitis have used the diluted tincture as a nasal wash.  Topically, purple loosestrife is used to treat varicose veins, eczema, sores, and wounds.  I’ve also seen it in skin care products as a nutritive, cooling astringent.
 

Studies

An extract of Lythrum salicaria was shown to have a clear antimicrobial activity against E. coli as well as antifungal activity against Candida albicans in this 1999 study out of Finland.

This study shows that an extract of the stems and flowers had a significant hypoglycemic effect on diabetic rats and mice

Purple loosestrife’s anti-inflammatory and antioxidant effect was confirmed in this 2006 study out of Turkey using in vitro and in vivo methods.  Scavenging free radicals and fighting inflammation are key factors in fighting a wide range of diseases including cancer, Alzheimer’s, and AIDS.  Further analysis of its constituents in this study show potential for this plant to protect against the development of colon cancer and leukemia.

An extract of the plant was confirmed to have an antitussive effect and act as a bronchodilator in this 2012 study, which compared it to the effects of codeine.

A soxhlet extract of purple loosestrife was shown to have anti-listerial activity in this study.  Listeria is a foodborne illness especially harmful to pregnant women, newborns, the elderly, and those with compromised immune systems.
 

Chemical Constituents

Flavonoids (isoorientin, isovitexin), salicarin, tannins (main component), pectin, anthocyanins, sterols.
 

Dosages

Taken as a tea: 1-2 tsp dried herb, steeped one hour, taken 2-3x/day

Taken as a tincture: prepared 1:5, dry extract, 30% alcohol, 40-60 drops, 3-4x/day (David Winston)
 

My own thoughts upon meeting purple loosestrife...

It’s only recently that I first met purple loosestrife.  I knew of the plant, but had never been taught how to identify it, much less its medicinal value.  I came upon it on a route I like to walk.  There is an abandoned housing development project in our woods that consists of only a paved road and some curbing with sidewalks.  It’s only open to foot traffic and isn’t maintained by the township.  It’s been left to nature’s devices for the last 20 plus years, and there are many native species of flora reclaiming their space.  Its presence felt familiar even from afar, so I stood eye-to-flower spike with the plant taking in the striking purple color, and the name came clearly to me (I looked it up in a guide when I got home to confirm).

I found it growing in the wetter, more low-lying areas along the lane in dappled sunlight.  It seems to like the margins there- in the ditch between the woods and the road between the wild and the more well-traveled, or just at the edge of the cracking pavement among the marsh grasses, willows, Queen Anne’s lace, and water hemlock.  I thought this coexistence between wet and dry could be a possible signature to its astringent and moistening qualities.  It didn’t seem to be crowding anyone out where I found it, but growing only in small groups here and there as part of an already established, diverse community. 

I didn’t get an “invader” feeling from it at all and almost feel sorry for the bad rap it’s gotten.  Maybe it’s causing a riot only in areas where its medicine is needed? Where there’s a higher prevalence of diabetes? Or social and environmental disconnect? Or where there’s environmental toxicity that only that plant can fix? Or as a sign that maybe we shouldn’t have disturbed that ecosystem in the first place? Or for someone struggling with major life changes? For survivors of a major trauma? Or for those who need to shift their perspective? Or for those who have trouble communicating their true meaning? 

I got a distinct message from purple loosestrife that it helps to heal places and people (maybe those who tend towards more damp/stagnant constitutions?) that have been “disturbed and deserted” and to heal, they need to reinvent themselves through major transition, letting themselves go fallow so that the wild parts of themselves can once again take root and flourish.  How different would our attitude towards this plant be if our first thought was “abundant & multi-faceted medicinal” instead of “kill it with plagues of non-native beetles”- a shift in perspective could be to the greater good of plants, humans, and the ecosystems we inhabit. 

 

Ruthie Hayes studies and practices the art of herbal medicine form her home in the wooded hills of southeastern Pennsylvania.  The proprietress of Mother Hylde's Herbal, Ruthie is also a licensed massage therapist and has received training in clinical herbalism from The Eclectic School of Herbal Medicine.  You can follow her blog at hyldebaer.com and find her remedies on Etsy.