Common name ~ Western Coltsfoot
Botanical Name ~ Petasites frigidus var. palmatus
Family ~ Asteraceae
Western coltsfoot flower stalks emerge just before or with new leaves from the rhizomes in late February to early March in the Pacific Northwest, generally speaking. Flowers are hairless achenes the seeds of which disperse in the wind very similarly to dandelion.
Basal leaves are deeply divided into 5 -7 lobes. Green and hairless above, wooly below.
Very juicy rhizomes grow just below the surface of the ground.
Coltsfoot grows near the edges of forests in or near streams, water runoff, ditches, and waterfalls.
A digging fork is usually needed to pry the rhizomes from the ground, but the preferable method of barehanded harvesting works well if care is taken. Clippers are sufficient to clip the leaves, although they can be easily broken off without damage or uprooting the rhizomes.
The sesquiterpene petasin found in western coltsfoot is a smooth muscle relaxant, which is so welcome in reliving convulses coughing during viral and bacterial infections, and allergic reactions. As smooth muscle is also found in the cardiac, digestive, and renal systems, petasin can be helpful with spasms in these systems as well.
Isopetasin in coltsfoot rhizome is antispasmodic and a vasodilator. Isopetasin inhibits the signaling of the calcium ion channel. Calcium channels govern muscle contraction, hormone and neurotransmitter release. Isopetasin stops shooting pain, pain transmission, chronic pain, seizure, hypertension, and migraines. “Calcium channel blockers prevent calcium from entering cells of the heart and blood vessel walls, resulting in lower blood pressure. Calcium channel blockers, also called calcium antagonists, relax and widen blood vessels by affecting the muscle cells in the arterial walls (1).”
Kaempferol, a polyphenol antioxidant, is anti-inflammatory, antispasmodic to smooth muscle and vascular walls, a vasodilator, and is neuroprotective. Kaempferol can be found in hawthorn flowers and leaves, dandelions, calendula, many brassicas, echinacea, fennel, oregano, elderberries, and nettles.
The leaves contain polysaccharides, glycosides, mucilage, and tannins.
The polysaccharides are anti-inflammatory and relaxing to the aggravated tissues of the lungs. They work as an expectorant and help to force out any surplus phlegm and mucus. Working together, flavonoids and polysaccharides present in coltsfoot enhance the immune system as well as encourage a vigorous respiratory system. It’s worth noting that eastern coltsfoot, Tussilago farfare, does not contribute much of the antispasmodic effects that petasites does.
Glycosides and tannins contribute to the anti-inflammatory effects and the flavonoids present in coltsfoot possess anti-inflammatory as well as antiseptic properties that help in providing relief from convulsions in the lungs and patients suffering from asthma and bronchitis attacks, promoting easier breathing. Mucilage in the plants tend towards soothing and protecting irritated tissue.
To note, young coltsfoot leaves contain pyrrolizidine alkaloids both saturated and unsaturated. As the leaves mature and grow to be at least dinner plate size, the PAs are no longer present, suggesting that the PAs might be part of coltsfoot’s defense system. PAs are hepatotoxic and carcinogenic (2).
“Ten new eremophilane-type sesquiterpene lactones, eremopetasitenins A1, A2, B1, B2, C1, C2, C3, D1, D2, and D3, sulphoxide bearing lactone, eremopetasinsulphoxide, and two methoxyl derivatives, as well as seven previously known sesquiterpenes have been isolated from fresh rhizomes of Petasites japonicus and their structures determined by spectroscopic techniques (3).” These type of eremophilanes tend towards obstructing protein synthesis, stimulating the digestive tract, inhibiting muscle spasms, cancer cells, parasites, serotonin release, and inflammation. It’s unclear if our local Petasites frigidus var. palmatus contain theses eremophilanes.
Coltsfoot can be helpful in treating neuralgia – sensitivity and soreness along the length of a nerve -, headaches and migraines, and spasms in the gastrointestinal system. Not for every day use, we utilize coltsfoot as a medicine vs nutritive or tonic plant. When harvesting rhizomes, care must be taken to remove small leaves and leaf buds.
Coltsfoot flower remedy helps a person to get unstuck due to grief, fear, or self imposed emotional immobility, and joyfully and with confidence move forward in life’s journey.
Preparations and remedies:
Fresh coltsfoot rhizome medicinal oil, crockpot method, for relieving shooting pain. Tincture (151 proof alcohol) and/or elixir of both fresh rhizomes and fresh mature leaves for relieving coughs, calming spasms of the pleura (lining of the lungs) and smooth muscle in other systems. Coltsfoot flower remedy.
Herb/drug interactions and contraindications:
Should be avoided by pregnant and lactating women due to the possible presence of pyrrolizidine alkaloids.
I use coltsfoot rhizome as well as willow, devil’s club, valerian, and other plants in my very effective pain relief salve formula. I love seeing coltsfoot when I’m out in the woods, because it represents being away from civilization and basking in the healing power of nature.
- http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.894.9974&rep=rep1&type=pdf also https://www.ema.europa.eu/en/documents/public-statement/public-statement-use-herbal-medicinal-products-containing-toxic-unsaturated-pyrrolizidine-alkaloids_en.pdf
- Motoo Tori, Makiko Kawahara, Masakazu Sono. (1998) Eremophilane-type sesquiterpenes From Fresh Rhizomes of Petasites japonicas. Elsevier Phytochemistry Volume 47, Issue 3, pp 401-409. https://www.sciencedirect.com/science/article/abs/pii/S0031942297005815