Table of Contents
- Edible Uses of Lady’s-Thumb
- Medicinal Uses of Lady’s-Thumb
- Alternative Uses of Spotted Smartweed
- Growing Polygonum Persicaria
A type of buckwheat, lady’s-thumb (Polygonum persicaria syn. Persicaria maculosa) is a common garden “smartweed” here. It’s a smart beginner wild edible and medicinal green because of the distinguished triangular purple spot on the leaf making it easily identifiable.
Check out the nice, clearest “thumb”print, bottom-left:

There are lookalikes throughout Ontario, primarily also in the buckwheat family, like the smaller prostate smartweed for instance. The most stunning native smartweed is like a deluxe version of lady’s thumb; that’s water smartweed.
Edible Uses of Lady’s-Thumb
The young leaves and shoots can be cooked and eaten. The young thumb-printed leaves are especially palatable. As they age the leaves get peppery, but they can still still be eaten raw, or cooked like spinach.
The seeds can be harvested and eaten whole. They can be pound them into a seed butter or dried and ground for flour too. Since you often find this one near lamb’s quarters, they’d make for some wild buckwheat-like pancakes mixed together. Lady’s-thumb is in the buckwheat family after all! I’m going to try this soon and I will report back. I’ll use some Haliburton maple syrup on these!
Medicinal Uses of Lady’s-Thumb
Lady’s-thumb is primarily said to support these body systems:
- Digestive
- Urinary
Medicinal tags include Astringent, Diuretic, and Styptic. See Medicinal tag key for more information.
Common usage includes the flowering stems as a soothing astringent tea for stomach pain. Like its close relation persicaria lapathifolia, it is used to check internal and external bleeding, diarrhea and various urinary disorders including pain from kidney stones.
Alternative Uses of Spotted Smartweed
A yellow dye can be produced with alum used as a mordant.
Growing Polygonum Persicaria
Like lamb’s-quarters, lady’s-thumb will grow where humans dig the soil. It’s naturalized, nonnative, along with some of its other relations are likely to just show up in yards and grassy paths and driveways. If you garden or a friend does, you should be able to find some especially healthy plants among your growing garden vegetables. Around Haliburton, the plant especially likes our acidic, peaty loam!
Water smartweed is a native relation that can grow in or near water and on land in moist soil.
WARNINGS
And the Usual Cautions:
1) Most medicinal herbs, if edible, are meant to be eaten in moderation, even sparingly. Some require extra preparation. Tannins are toxic if consumed in excess. Before taking any new supplements, you should consult with a healthcare professional.
2) A vast amount of these herbs are diuretic. (See the Medicinal tags above to check if this featured herb is one of them!) Diuretics are generally safe, but they can be risky for people with other medical conditions or who take certain medications. Please consult your doctor if you have any health conditions.
3) People can be allergic or sensitive to nearly any plant; try new herbs one at a time at your own risk. For instance, saponins commonly cause stomach upset.
4) For serious medicinal use, I must recommend receiving a diagnosis and working with a reputed health care provider. I generally do not post specific treatments and dosages because I think that is best between you and your health care provider, and ideally monitored.
5) Anyone pregnant, nursing, or taking prescription drugs should talk to a health care professional before adding new food items to their diet.
6) Many plants have look-a-likes, and sometimes they are poisonous.
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REFERENCES
My new favourite foraging book is Sam Thayer’s Field Guide to Edible Wild Plants: of Eastern and Central North America (The Sam Thayer’s Field Guides) Paperback – June 1, 2023 and this plant IS featured as one of the edible wild plants in this area. I highly recommend this guide for your bookshelves!
Persicaria maculosa Gray – Database of Vascular Plants of Canada (VASCAN)
Field Guide to North American Edible Wild Plants (Out of Print)
How Indians Use Wild Plants for Food, Medicine & Crafts (Native American)
Hello so the persicaria is not a problem to eat? Lapathifolia I mean
THANKS
Yes, it’s edible/interchangeable.