Yellow pond lily

What is Yellow pond lily?

Yellow pond lily is a water plant that grows in ponds and slow streams across North America. The part used in folk medicine is the thick underground root, called a rhizome. Spatterdock and cow lily are other names for the same plant.

American folk healers, and the Eclectic doctors of the 1800s, used the root as an astringent. An astringent is something that tightens and dries tissue. They put it on sores and used root washes for irritation.

Human evidence for any of this is essentially absent. There are no good trials in people, so every claimed benefit on this page is unproven. Long traditional use is not proof that a remedy works, and it is not proof that it is safe.

How does Yellow pond lily work?

No one has shown how yellow pond lily works in a person. What follows is laboratory work and old theory.

The root is rich in tannins. In test tubes, tannins bind protein and tighten the surface of tissue. That is the old idea behind using the root on sores and for loose stools.

The root also holds nuphar alkaloids, plant chemicals that contain sulfur. In cell studies, some of these kill cells and set off cell death. In lab dishes, a few also slow the growth of bacteria and parasites.

Whether any of that happens in a living body is not known. Absorption, dose and safety in people have not been studied. So the mechanism stays a hypothesis, an untested idea.

What forms does Yellow pond lily come in?

Yellow pond lily is hard to find in shops today, and most herb ranges do not carry it.

Forms you may see: - Dried root, cut or powdered - Root tincture, an alcohol extract - Loose root sold for tea

Older folk forms, no longer advised: - Mashed root laid on sores as a poultice - Strong root tea used as a skin wash - Root tea used as a douche, a wash inside the vagina

There is no standard strength for any of these. Makers do not test for alkaloid content. One batch can differ a lot from the next.

Leaves and seeds are gathered now and then. The root is the part with the medicinal history.

Where it comes from:

Several Native American nations used pond lily roots. They mashed the root into poultices for sores, boils and swellings. Seeds of related pond lilies were also gathered and eaten.

The Eclectic doctors of 1800s America took the root into their books. They listed it as an astringent and used it for discharge and sore throats. Washes, gargles and poultices were the usual forms.

Some old texts claimed the root damped sexual desire. That claim was never tested and no modern work supports it.

Use faded through the 1900s. Today the plant is a minor herb kept alive mostly in historical writing.

What does Yellow pond lily help with?

• Sores, boils and skin swellings (poultice): This was the most common folk use. Healers mashed the fresh root and laid it on the skin. No human trial has tested it. Tannins do tighten tissue in test tubes, but that is not proof of healing. An infected boil needs medical care, not a plant poultice.
• Vaginal discharge (historic wash): Eclectic doctors used a root tea as a douche for discharge. The idea was to dry and tighten the tissue. There is no evidence that this works, and douching itself is now advised against. It can upset the normal balance of bacteria and push infection higher. New or changed discharge should be checked by a doctor.
• Diarrhoea: Astringent roots were a standard folk answer to loose stools. The tannins were thought to firm things up. No trial has tested yellow pond lily for this. Tannins in general can firm stool, but they can also cause nausea. Oral fluids and salts remain the proven first step.
• Sore throat and mouth irritation (gargle): Old texts list a root gargle for raw throats and inflamed gums. The dry, puckering feel of tannins was taken as a sign it was working. That feeling is not the same as healing. No study has measured whether it helps. Salt water is cheaper and better understood.
• Reducing sexual desire (historic claim): A handful of 1800s writers listed the root as an anaphrodisiac, meaning something that lowers sexual desire. Nothing supports this. No animal or human study has shown such an effect. Treat it as folklore, not as a property of the plant.

What are the side effects of Yellow pond lily?

• Upset stomach and nausea
• Vomiting after larger amounts
• Constipation, or in some people loose stools
• A dry, puckered feeling in the mouth
• Skin rash or itching where it was applied
• Stinging of soft tissue, such as inside the vagina

Good to know:

Reports are old and informal, so no one knows how often these happen. Short-term stomach upset and mouth dryness are the usual complaints from tannin-rich roots.

The bigger issue is what has not been checked. The alkaloids have never been tested for liver, kidney or long-term effects in people.

How much Yellow pond lily should you take?

• Recommended daily: This page gives no dose, and that is deliberate. Yellow pond lily is rarely sold, and no safe amount has been agreed by anyone. Old books listed amounts, but those figures were never tested for safety. Modern products are not standardised, so a stated amount would mean little. If you are thinking about using it, speak to a doctor or a trained herbalist first.
• Best time of day: Time of day does not matter, because no effect has been proven. Tannin-rich roots sit worse on an empty stomach, so morning on its own is not a good plan.
• With or without food: If taken by mouth at all, food makes stomach upset less likely. Tannins can cause nausea on an empty stomach. Keep it well away from iron tablets.
• Time to effect: Unknown. No study has measured how long anything takes. It may do nothing at all, and you should expect that outcome.
• How long to take it: No safe length of use can be given. Folk use was short and occasional, mostly on the skin. Repeated or long-term use has never been studied in people.