The Science of a Lucky Charm: Four-Leaf Clovers

Update (added June 8th, 2012):
Scientists have now discovered the gene responsible for creating a four-leaf clover, using molecular markers, according to research published in the July/August 2010 edition of Crop Science.

The white clover plant is actually a genetically complex organism. The gene for four leaves is rarely expressed and environmental factors also contribute. So the answer for why four-leaf clovers exist in white clover is a combination of a rare gene and environmental conditions.

It has been hard to discover the gene up until now because it is hidden by the allele for three leaves. The use of molecular markers made the discovery possible.

The variation in white clover (trifolium repens). Credit: billaday via Flickr

The variation in white clover trifolium repens. Four-leaf clovers are considered lucky. (Credit: billaday via Flickr)

(NOTE: I decided that since St. Patrick’s day was moved to the 15th, but is generally on the 17th, I would split the difference and post my themed post on the 16th)

Four-leaf clovers: the rare, sought-after variation of the more common three-leaf clover. It is said to be lucky, and indeed, you’d be lucky to find them. Some statistics state that there are 10,000 normal three-leaf clovers to every four-leaf clover.

I somehow think that is a little exaggerated. I myself have found 3 four-leaf clovers in my life time… mostly before I was out of grade school and had plenty of time to gaze at the grass where White clover, Trifolium repens, grew.

Some people try to claim they’ve found a four-leaf clover, but often they have just picked the leaf of a plant that consistently produces four-leaves, such as Pepperwort (Marsilea Quadrifolia) or Oxalis (any variety).

But what causes a true clover to produce this variation? Obviously it is a variation— the scientific name for clover, Trifolium, means three (tres) leaf (folium). A real four-leaf clover also has a fourth leaf that is often smaller than the rest.

The truth of the matter is that scientists are unsure of the exact cause of four-leaf clovers, and indeed, there may be more than one factor causing this variation. However, here is a list of possible causes.

  • Environmental:

To suggest an environmental factor, seekers of the lucky leaflet have found that certain patches of clover were more likely to have four-leaf clovers. This occurrence suggests that environmental factors such as soil pH, soil composition, pollution of the area, or other influencing factors. Some suggest that environmental stressors produce more variation, but this is unknown.

  • Genetic:

Taking into consideration the rarity of the four-leaf cover, it is possible that the variation is not so much a mutation, but a recessive gene that crops up occasionally. Personally, I think this a little unlikely. I would expect to see a little more four-leaf clovers. There also exist variations with more than four leaves, which is not explained with genetics naming a single gene.

  • Mutation:

This one is my favorite possibility for the origin of the four-leaf clover. All multi-cellular organisms have some mutation occurring. Mutation is a fun word, but it is a good thing and creates variation within a population. Mutations are “changes to the nucleotide sequence of the genetic material of an organism.” Basically, a mutated organism is just a little different from its fellows. In four-leaf clovers, the mutation is most likely somatic, meaning the mutation occurs in the somatic cells. Somatic mutations in plants can sometimes be are not passed down to their offspring. They are mutations that occur after the plant is started.

  • All of the above:

It is possible that in some specimens of four-leaf clovers, more than one of these factors contributed to the variation.

Good luck with finding the four-leaf clover. The three-leaf clover is supposed to represent the holy trinity, so the four-leaf clover represents God’s grace. Most people associate the white clover as the true shamrock, although shamrock simply means “little clover”. Other sources say each of the leaves mean something, like hope, faith, love, and happiness.

Posted on by Kallen in Features

14 Responses to The Science of a Lucky Charm: Four-Leaf Clovers

  1. lk

    all in all.. It’s gotta bring a little luck!

  2. Jyvyn

    I’d like to toss in the idea that pesticide use (falling into the environmental category) would be quite plausible. I myself have found probably around 10 lucky clovery charms in my lifetime. With any amount of time of searching, one can usually be found in a substantially large patch.

    It is comforting to know that scientists haven’t figured it out yet, meaning there are mysteries yet to be uncovered. Perhaps that is what makes these the lucky charms of Ireland!

  3. Penny

    just yesterday i found 6 four leaf clovers and 1 five leaf clover in a patch in front of my school. And in elementary school four leaf clovers grew like grass around the trees.

  4. ELLEN

    I WAS IN Bumpass, VIRGINIA, and My daughter and I found 30 4-leaf clovers in about 6 different patches in our lawn over about the time-span of 2.5 hours. They were amongst 1000’s of other clover…

    We didn’t know what caused SO Many to grow…perhaps we’re near a nuclear power plant?

    It was unbelieveable… She’s taking them in for show & tell tomorrow.

  5. Sonja

    My husband found 4 four leaf clovers in a day, and I must say that since then our luck has definately changed for the better since then. I asked my mum about the significance of finding these and she told me “make a wish but don’t be greedy when you do” My husband and I made a wish and it happened! because of the luck we got from these we also felt that we had to share our luck with someone else, so we passed one of the clovers on to a needy friend and they have also improved their quality of life. I don’t know if it was the wish or just the faith in what the clover represents, but when I wish upon the clovers, things just get better in all ways.

  6. Lara

    My brother calls me the Four-Leaf-Clover-Princess. I’ve had a knack for finding them throughout my life and have probably found a couple hundred in over 30 years. I have several 5-leafs and two 6-leafs. I usually give them to friends with exception of the 6-leafs. On my brother’s 25th B-day I gave him 25 4-leafs & 1 5-leaf. But for the past year I’ve been collecting them to make some sort of collage of clovers or something. In the past year I’ve found almost 50-only during the warm months. I LOVE CLOVERS !!!

  7. Lee

    I think anyone who says a 4-leaf clover is a hard thing to find either does not have a lot of time to spend outdoors (who does nowadays?); or else they live in an area where clover is not very prolific. Without actually trying to go out clover hunting, I have encountered a lot more than one in 10,000! If there were 10,000 clover for every 4 or 5 leaf variety I have found, then the college campus I went to would have been completely overrun with nothing but clover. We started ignoring four leaf clovers b/c there were so many. We would pick up the 5 leaves and above. The most radical one i ever got was a 7. I have to wonder what would have happened if i ever had had the time to actually go looking for them there.

    I suspect, though, the prolific nature of these on that campus might have had something o do with the fertilizer they used. Wherever they used it, 4 leaf clovers were common. I never did get the name of the stuff they used though :^(

    Also – when you find one – look for another in the same patch – close by. I have never seen this to fail (unless a rabbit or woodchuck had lunch there). Today I found one 5 leaf – just passing by. I immediately started to try to find its “twin.” It took me about 10 seconds. In the process, I found a 4 leaf. So I looked for its twin. That took another 10 seconds.

    I also use the term “twin” loosely b/c they are no identical. One has all 4 leaves the same size and the other has one leaf smaller. The 5’s were also like this.

    I wish i could find out more about this – but so far I cannot find out any reasoning online. It will be nice when we finally have reached the place we understand the DNA code. We will look back at these days and wonder how we ever survived such a primitive time.

  8. Jeska

    i also have found hundreds of these clovers in my lifetime. After a while you can look at a patch and immediately tell if it yields 4-leaf ones or not by the pattern of white on them and the shape of the leaves.

  9. Kelly

    I was locking up my bicycle in my backyard today when I spied a four-leafed clover. I reached down to pick it, and as I was standing up, I saw another… and another… and another. I all I found 12 four-leafed clovers and one five-leafed clover. This makes about 25 four-leafed clovers in my lifetime, and the one that I found today was only the second five-leafed clover that I’ve found in my life (sadly, the other shriveled and crumbled to dust before I could press it in a book). I know that they’re mutations, but I still feel lucky when I find them.

    It may be because white clover is more common, but I almost never find four-leafed specimens on red clover plants (I’ve only found two so far).

  10. Fuz

    “In four-leaf clovers, the mutation is most likely somatic, meaning the mutation occurs in the somatic cells. Somatic mutations in plants can sometimes be passed down to their offspring.”

    Just being nit-picky… a somatic mutation occurs in the somatic cells – the body cells, as opposed to the gametes (reproductive stuff). Only mutated cells in the gametes can pass on mutations to the offspring. Somatic mutations are NOT passed on. …well, not as far as I’m aware at least, though they do teach biology somewhat simplified here at times..

  11. Paul

    Once I found 25 four leaf clovers and 2 five leaf clovers in one day.

  12. poppy

    I had a patch in my garden when I was 6-7 that consistenly produced 4 leaf clovers- we’d literally locate several a day, even once a 5 leaf clover! We moved and I’ve found only one since, so there must have been a little magic in the soil there :)

  13. Kallen

    With the update to this post, I’ll respond to a few comments!

    @ Jyvyn: Well, they’ve discovered the reason why now! I’m sure there are still plenty of mysteries left though.

    @ELLEN: take comfort… because its a genetic reason, I don’t think you have to worry about that nuclear power plant anymore!

    @Lee: Well, they’ve gotten a little bit closer to understanding genetics, thanks to molecular markers. Click on the link in the update to learn more on the Crop Science website or visit

    @Fuz: You are totally correct… that’s somatic mutation for you. I’ve fixed the language, thanks for your vigilance!

    @poppy: Environmental factors play a part, so there may be a little “magic” in the soil of your old garden.

  14. Jessica

    This year on the side of my house there is a patch of clover (not oxalis or pepperwort) that has an inordinate ammount of four leaf clovers in it (the majority are 3 leaf ) but this st pattys day I found 34 of them with no trouble. (will be happy to post photo if you wish) I do have large clover patches through out my yard (grass mono cultures are so boring) It seems to be just this patch that has the lare % of them, thinking maybe genetic. Anywho, I was just out taking out the trash and spotted 4 of them and it made me look this post up. :)

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