You’ve probably walked on it without knowing it. It’s a small, discreet plant found in meadows that produces magnificent yellow flowers, sometimes speckled with orange. It’s very abundant in our countryside, and it has properties that a famous French herbal doctor discovered by pure chance, as we will see.
In this episode, I will be presenting birdsfoot trefoil.
Before we start, a quick but important reminder: I am not a doctor, pharmacist, or licensed healthcare professional. The information shared in this episode is for educational purposes only. It is not intended to diagnose, treat, or cure any condition, and it does not replace professional medical care. Always consult your physician before starting any new herbal protocol, especially if you are pregnant, nursing, or taking medication.
Let’s start with some botany. Birdsfoot trefoil is a perennial plant from the Fabaceae family. Its latin name is Lotus corniculatus. You’ll find it in many countries around the world. It’s herbaceous (meaning it doesn’t produce wood over the years, unlike other perennial plants). It’s relatively low-growing, sometimes lying close to the ground. You generally find it on lawns, in fields, on embankments, and along roadsides. Very common in our countryside.
The leaves are alternate and trifoliate (so it has 3 leaflets), with 2 stipules that form a group of 5 with the 3 leaflets. So it looks like 5 leaflets, but technically, they’re 3 leaflets and 2 stipules. Yes, I know, botany has its own language, and it is very precise in terms of words.
We have clusters of flowers. These are typical Fabaceae flowers—so 1 standard, 2 wings, and a keel composed of 2 petals. The color is generally yellow but you will also find orange versions, and sometimes it can lean toward red.
The fruit is a pod, typical of the Fabaceae, and this pod is extended by a small horn, which is where the latin name “corniculatus” comes from. And the name “bird’s foot” comes from the way the pods are arranged like a fan.
It’s quite polymorphic, meaning certain characteristics of the plant will vary depending on the environment. You can have variations in size, leaflet shape, flower color, and hairiness. This can seem a bit confusing if you haven’t seen these different variations in nature, because you might think they’re different species. But they are not. So as always, get help from people who know the plant if you want to identify it in nature. Or get a good botany reference book for your region.
The parts used are either the flowers or the flowering aerial part (so leaves, flowers, and stems). As we will see toward the end, just the flowers seem to be a better option.
Harvesting happens at flowering time, which can last several months. Generally, peak flowering occurs around June–July in many regions.
You cut the parts you’re interested in, dry them flat on a rack in a dry place, and you can keep them dry or transform them fresh—we’ll talk about forms and preparations in a few minutes.
As for the constituents, we have 3 major classes:
The energetics: cooling (to the nervous system, to inflammation thinks to its flavonoids) and to me, slightly moistening (even though it contains quite a bit of tannins… this is all a bit subjective, so take my evaluation with a grain of salt).
Now let’s talk about the medicinal properties of birdsfoot trefoil. To do this, we’re going to bring in a great French doctor named Henri Leclerc who greatly contributed to the modern practice of herbal medicine in France. He’s more or less the one who brought birdsfoot trefoil into the French pharmacopoeia. Let me tell you the story.
One of his patients, who was a farmer, had conjunctivitis and was very nervous, which gave her heart palpitations and sleep issues. For her conjunctivitis, Leclerc asks her to prepare an tea of sweet clover to make an eyewash. And back then, Leclerc works with a lot of countryside folks who know their way around with plants.
Except the patient makes a complete mistake and uses birdsfoot trefoil instead of sweet clover. And instead of using an eye wash, she drinks the tea. Result: Her eye situation doesn’t improve at all. But what’s surprising is that her nervousness improves. In less than a week, she’s sleeping well, her heart palpitations calm down. And Leclerc decides to investigate.
He tests birdsfoot trefoil on other patients with the same nervous symptoms. And bingo: it wasn’t just luck, it was really the plant that was working. A beautiful discovery, but completely by accident.
This brings us to the properties and indications:
So overall, the profile of birdsfoot trefoil: calming, relaxing, soothing. It slightly lowers blood pressure when it has a neurogenic component—which means the state of the nervous system drives the blood pressure spikes. And it relaxes the person who is tense as a guitar string.
You can make good combinations in the form of herbal teas or tinctures with sweet clover or sweet woodruff to create a calming effect before bed. And it will taste delicious. With hawthorn and motherwort to calm cardiac hyperexcitability, with your doctor’s agreement, of course.
You can combine it with St. John’s Wort for situations of mild to moderate depression or seasonal depressions. With hops for difficult nights, if there are no contraindications. I’m not going to mention the contraindications of the plants in these combinations—I’ll leave that to you to consult the various fact sheets on my site or elsewhere; otherwise, we will be here for hours. But it’s important to go check.
A small note about birdsfoot trefoil for sleep disturbances: in the French tradition, it has this reputation of helping a person when there are nighttime awakenings. That is its specialty. Maybe the person has no trouble falling asleep, but wakes up during the night and has difficulty falling back to sleep. In which case, you would take it just before going to bed (in the form of a tincture because a tea might make you get up to pee), and you might keep a dose of tincture for the first nighttime awakening if necessary.
As for forms and dosages:
Why did I mention possible combinations with other plants? Is the plant not usable on its own, properly dosed, and over long periods? Based on the data we have available, perhaps not.
It contains what we call cyanogenic glycosides. These glycosides will be broken down to produce hydrocyanic acid, which is toxic. Now, we’re not going to panic. These are small quantities. But we need to take this into account.
You’ll find them in certain phenotypes of birdsfoot trefoil—certain variations, if you will—that are almost impossible to distinguish from others. To put it more simply, some birdsfoot trefoils will contain more cyanogenic glycosides than others, and you won’t be able to tell which ones. This will also vary according to the season (Foulds & Grime, 1972).
I found one study saying that cultivated species seem to contain much more than wild species. That said, wild species do contain some (Blaim, 2015). All references are on my website if you want to go further.
This hydrocyanic acid is released after tissue damage, for example when the fresh plant is cut or macerated in lukewarm or hot water (with a temperature above 104°F/40°C) (Conn, 1979).
Drying significantly reduces the release. That said, not completely, and a tea of the dried plant, or a tincture of the dried plant, can still contain traces (up to 5 mg/kg of dry matter, Vetter, 2000).
The flowers are less concentrated in cyanogenic glycosides than other parts of the plant (0.1–0.5 mg/g of dry matter). That said, they contain a small amount, especially during active flowering periods (Foulds & Grime, 1972).
Small amounts of hydrocyanic acid will be detoxified by the liver. That said, larger amounts can overload the liver’s capacity and create cyanide poisoning.
In Belgium, its commercialization as a medicinal plant is regulated because of this risk (Royal Decree of 1997).
That’s it with the raw data. Now, here’s what I’m going to conclude from this, to maintain a certain precautionary principle:
That’s it for my conclusions. My goal here is not to scare you, but to give you the information. We cannot sweep all this under the rug. That said, other plants contain cyanogenic glycosides like passionflower. For Passiflora incarnata, the leaves contain some of those glycosides (and that’s the part used in herbalism). But the studies don’t give concentrations, so I can’t compare with birdsfoot trefoil levels.
As for me, it’s a plant I’ve tested on myself. It’s a plant that I’ve recommended to certain clients I work with, and I don’t intend to remove it from my toolkit. But I do intend to follow the precautions I’ve listed for you.
And that’s all for birdsfoot trefoil. Thank you for being here. I will see you very soon for the next episode of TheFrenchHerbal!
Gürağaç Dereli FT, Khan H, Sobarzo-Sánchez E, Akkol EK. Antidepressant Potential of Lotus corniculatus L. subsp. corniculatus: An Ethnobotany Based Approach. Molecules. 2020 Mar 12;25(6):1299. doi: 10.3390/molecules25061299. PMID: 32178424; PMCID: PMC7144109.
EFSA (2019). Scientific Opinion on the risks for human health related to the presence of cyanogenic glycosides in foods. EFSA Journal, 17(12), e05922.
Vetter, J. (2000). Toxicity of cyanogenic glycosides in food. Journal of Food Composition and Analysis, 13(2), 173-180.
Foulds, I., & Grime, G. P. (1972). The distribution of cyanogenic glycosides in Lotus corniculatus. Journal of Ecology, 60(3), 751-761.
Conn, E. E. (1979). Cyanogenic compounds in plants and their pharmacological effects. Phytochemistry, 18(5), 759-764.
SPF Santé publique (Belgium). (2026). Liste des plantes réglementées en médecine non conventionnelle. Arrêté royal du 29 août 1997 (modifié en 2021).
Blaim, H., & Nowacki, E. (2015). Cyanogenesis in Lotus and Trifolium species. 19-26. https://doi.org/10.5586/aa.1979.003
