Friday, March 8, 2013

Phony Shamrocks and Fake Four-Leaf Clovers

~ Jessica S. Herwick

Don’t be fooled this Saint Patrick’s Day by the variety of plants whose leaf shape, coloring, or number of leaves imitate those of the elusive four leaf clover.  Many of those lucky charms you might collect at your local bar, or wear during the neighborhood pub-crawl on Saint Patrick’s Day could actually be a number of other plants!  

You would be surprised how many manufacturers sell you a four-leaf water clover or a piece of oxalis foliage!  Collected here for you are the facts about true clover and the top four-leaf clover impersonators, so this year, you won’t be fooled!

An honest-to-goodness four-leaf clover is a rare variation of the authentic Irish Shamrock, a three-leafed clover produced by the herbaceous perennial, White Clover.  Scientifically speaking, Trifolium repens.  Literally translated, the scientific name means three leaves creeping – tri (from the Latin tres meaning three), folium (Latin meaning leaf) repens (Latin meaning creeping).  

To find a real four-leaf clover, first you must identify this typically three-leafed white clover and search carefully through the mounds for the rare and lucky four-leafed variation.  According to scientists, you have a one in ten thousand chance!  For every four-leaf clover that grows, ten thousand typical three leafed clovers exist.  Considering how many parts of the world this hardy herbaceous plant is established, those aren’t terrible odds! 

White clover contains 3 egg shaped leaflets that most often display a white watermark or herringbone imprint that usually fold into a v-shape towards the base of each leaflet.  When a variation occurs, the fourth leaf on a four-leaf-clover is usually noticeably smaller than the other 3 leaves.  Notice the leaflet in the bottom right corner of the four-leaf clover photograph above!

You may spot small, globe shaped white or pinkish-white florets shooting upwards from mounds (stands) of white clover on stalks that rise up from the leaf axles.  The nectar from these flowers is attractive to bees and especially to a particular case-bearer moth known as Coleophora mayrella, who is so particular, it will only feed upon white clover.  Note also that you may find small pods (legumes) roughly 4mm long if the season is right.

Aside from being endowed with the luckiest of reputations, white clover has a number of beneficial qualities.  It is a hardy groundcover that can out-compete most other weeds you would otherwise find settling into your lawn or turfgrass, which makes it a popular addition to your lawn or grazing areas.  It fixes nitrogen in the soil and it’s spreading, solid stands aid in the prevention of erosion, particularly on moist fertile soil areas. 

White clover is a popular forage crop for livestock, popular among organic graziers and wandering Easter Bunnies.  It grows in abundance, is high in proteins and tasty to the palette!  Technically a legume, humans can ingest these plants as well.  It is an often used survival plant, so if you find yourself lost in the woods or a bear eats your granola on the next hiking escapade, you can fend off starvation and dehydration by munching on white clover leaves until help arrives.  When eaten raw, the leaves may be difficult for human stomachs to digest, but can be cooked (when in civilization) and added to salads or soups for a protein boost and a happier belly.  

Although it is not recommended in modern times, before refined medicines existed, white clover grew in abundance in a variety of regions and was utilized as a medicinal plant by a number of Native American tribes including the Cherokee, Delaware and Algonquin.  All of these tribes prepared white clover to make medicines that treated a number of ailments.

Trifolium repens' reputation goes back even further to very ancient times.  White clover was highly regarded by the Druids in Ireland who believed the four leafed finds to be a sign of luck, and would practice sacred rituals in groves where four-leaf clovers were found.  The Celts in Wales believed them to be a charm against evil spirits and would carry four leaf clovers with them on long, dangerous journeys for protection.  

Until recently, there was a great botanical debate about what caused the four-leafed variations to grow within the three-leafed clover mounds.  Some believed it was caused by something in the environment that triggered the variation.  Some believed that it was pure genetics, a recessive gene that appeared less often than a typical recessive variant.  A third group of believers invested in the search for proof that the four leaves were caused by a mutation.  

In 2010, researchers at the University of Georgia and the Samuel Roberts Noble Foundation in Ardmore, Oklahoma have started to put an end to this debate by publishing several exciting findings on the mysterious leaf trait inheritance in white clover in the July-August issue of Crop Science.  The researchers discovered that there is a gene that turns ordinary three-leaf clovers into the rare and sought after lucky four-leaf clovers.   This gene is masked by the gene for three-leaflets, making it extra tricky to spot. Additionally, they discovered that the presence of the gene for the four-leaf trait is strongly influenced by the environmental conditions surrounding the plant, so practically everyone was right! Now that molecular markers are available to detect the presence of the four-leaf gene, breeders can work with it, and who knows?!  Soon, we may see the production of plants that produce true four-leaf clovers in abundance!  


FAKER #1      Marsilea 
Marsilea is a genus of approximately 65 species of aquatic ferns that belong to the family 
Marsileaceae.  Unlike your typical fern, these multi-leaved pond plants have their own unique look.  At the end of the long-stalks that shoot up from the water are leaves containing four clover-like lobes that sit above the water surface, or submerged, depending on the stage of plant growth.  Marsilea quadrifolia and Marsilea polycarpa are the biggest impostors of this genus, and resemble the four leaf clover so closely that many refer to these plants as waterclover, most commonly, European waterclover.
Waterclover is found in many locations globally including central and southern Europe, North America, Afghanistan, Southwest India, China, and Japan.  Varieties of Marsilea have been well established in the Northeastern States for over 100 years.  Some cultures used the juice from this plant to treat snakebites and abscesses due to it's anti-inflamitory properties, which I suppose might make this a lucky plant if you've been bitten by a diamond back, however, it will not bring you the luck of the Irish.  

FAKER #2      Oxalis
This impostor is the easiest to discover.  Oxalis is the largest of the genus within the Oxalidaceae (the wood-sorrel) family, containing 800 of the estimated 900 plants that fall under this family name.   Numerous species of Oxalis have been referred to commonly as false shamrock, and for good reason.  From a distance they look like twins, unless they are flowering, which can make things easier. Most varieties sport 3 or 4 leaves and grow in clumps that closely resemble white clover.  Oxalis blooms in pinks, yellows and whites and the flowers are nothing like those of the white clover, making it easy to tell the difference. 

A striking characteristic of this genus (and a major reason for their name) is the oxalic acid they contain, giving the leaves and flowers a sour, tangy, acidic taste when chewed.  This is reminiscent of Sorrel proper (Rumex acetosa) and explains the common names given to many varieties, like wood sorrel or sourgrass.  

* In very large amounts, oxalic acid may be considered slightly toxic to humans, interfering with proper digestion and kidney function. It should be noted, however, that the amount would have to be unusually large for a typical person in good health to feel effects.  Oxalic acid is also contained in more commonly consumed foods at similar levels – including but not limited to - spinach, broccoli, brussel sprouts, grapefruit, chives, and rhubarb.

Except for the Polar regions, many colorful varieties of Oxalis can be found most anywhere across the globe, and as a result, it's been incorrectly identified as a four leaf clover in a variety of countries all over the world.  
Now you know better, Philadelphia.  
May the luck of the Irish be with you this Saint Patrick's Day!

Where To Go For More Information:

USDA Fact Sheet on Trifolium repens L. (White Clover)

To purchase the article or review the abstract from Crop Science:
Journal reference: Crop Science, DOI: 10.2135/cropsci2009.08.0457

Virginia Tech Weed  Identification Guide (even though it's not technically a weed!)

1 comment:

  1. I found a four leaf something today and picked it just in case, figuring if it had the v-shaped white things on it, which it did, it was a real clover. It grew with a clump of other (three-leafed) plants that I also thought were clovers, but I was informed by a boy in my class that it couldn't be a "real" four leaf clover because the leaves didn't have a small indent in them to make it look like a clover. After reading this and upon studying the pictures of Marsilea and Oxalis, I realize that this can't possibly be them, first of all because of the v-shape they both lack, but also the coloring, and the fact that I recognize Oxalis as the only plant I know of that "pees". (We find it at my father's house vacationing surrounded by water, despite the fact no one watered it or watered around it.)

    I also studied the picture of your three-leafed clover, and realized my four leaf clover looked exactly like it if not for having an extra leaf and no indentation. So I have something that looks exactly like a four leaf clover and isn't.