Difference Between Shamrock, Clover, and Oxalis Plants

By Judy Stout

We all know what a shamrock is…or do we? There are several plants commonly called “shamrock”. Most are species of clover and oxalis and, while each species can be beautiful and interesting in its own right, they’re not all associated with the true shamrock. So what is the identification of the original shamrock that is at the heart of so many Irish traditions?

Brief History of the Shamrock

The shamrock has become an international symbol of Ireland and its culture, and it’s featured in celebrations such as St. Patrick’s Day. In Irish mythology, the shamrock was said to have been used by St. Patrick to explain the concept of the Holy Trinity to the pagan Irish people – each leaf representing the Father, Son, and Holy Spirit in one divine essence. This association with St. Patrick has made the shamrock an enduring symbol of both Christianity and Irish identity.

The answer to which plant was the original shamrock was lost over time and remains a point of debate. A shamrock is characterized by its three leaves (or four if the “lucky” four-leaf clover is taken into account). So, while the plants most recognized as shamrocks are usually the common white clover (Trifolium repens) and wood sorrel (Oxalis acetosella), other three- or four-leaved plant species may also be referred to as shamrocks.

With all the potential for confusion, it might make more sense to view the shamrock as a symbol and not focus on a specific plant. Especially when it’s so common these days to find both, Oxalis and Trifolium plants, being grown and marketed as clovers or shamrocks.

Beyond the live plants, you can find representations of shamrocks in art, fashion, sports, and even corporate logos as they continue to symbolize luck as well as Irish heritage. The enduring legacy of this humble plant reflects its deep roots in both history and culture—a testament to its significance across generations.

Characteristics of Clover

When exploring the differences between clover and oxalis, it’s essential to understand their distinct characteristics. Clover, belonging to the Trifolium genus, is often recognized for its three-leaflet structure and the Trifolium repens species is thought by many to be the most likely origin of the iconic shamrock.

Clover plants typically feature rounded leaflets and produce small, spherical flower clusters that can be white, pink, or purple depending on the species. Clover can spread by seed or through rhizomes and will form a dense mat of foliage over time.

Dutch clover (Trifolium repens) is especially popular with gardeners. It’s known for its vibrant green foliage and charming white flowers that are a favorite for bees and other pollinators. It makes a versatile ground cover that offers numerous benefits to gardeners. Its characteristics include a low-growing habit, drought resistance, and the ability to fix nitrogen along its roots and help nourish the soil, making it an excellent choice for improving soil health.

Growing Dutch Clover

To grow Dutch clover successfully, start by selecting a location with well-drained soil and partial to full sunlight. Although it can tolerate various soil types, Dutch clover thrives best in loamy or sandy soils. To establish Dutch clover, follow these steps:

1. Prepare the area by loosening the topsoil and removing any weeds.
2. Sow seeds directly into the prepared soil in early spring or fall when temperatures are mild. The rate of application for home lawns is ¼ to ½ pounds of seed per 1,000 square feet.

• Lightly rake the seeds into the soil, ensuring they are not buried too deeply as they require light for germination.
• Water gently but consistently until seedlings establish themselves.

Once established, Dutch clover requires minimal maintenance; however, regular mowing can help maintain its height and promote denser growth. By incorporating Dutch clover into your garden or lawn care routine, you can enjoy its aesthetic appeal and reap the environmental benefits such as improved soil quality, soil nourishment, and reduced erosion.

Red Clover

While Dutch clover is a favorite for lawns, red clover (Trifolium pratense) has become a favorite for using as a cover crop or in a crop rotation plan for a vegetable garden. Like Dutch clover, red clover benefits the soil by fixing nitrogen in the roots. Its deep roots can also help break up compacted soil as well as reduce erosion by holding soil in place. Red clover also helps suppress weeds and, if allowed to remain in place through its flowering period, the colorful blooms support a wide array of pollinating insects.

Dutch Clover – Friend or Foe?

One of Google’s highest ranked searches regarding clover is “how to kill clover in a lawn without killing the grass”. The perception that clover is a weed that needs to be destroyed is unfortunate. Before herbicides became readily available for home gardeners and lawn services, the Trifolium species of clover were common in lawn seed mixes. Their ability to fix nitrogen in the soil and generally improve soil health was a recognized benefit.

These days, as more homeowners seek ways to reduce the use of herbicides, as well as support pollinators, the use of clover in lawns is making a comeback. The demotion of clover to the status of a weed is gradually reversing as gardeners once again learn to appreciate its many environmental benefits. Along with its charming appearance, clover also provides a source of nostalgic activities such as hunting four-leaf clovers, or making a necklace or flower crown by tying stems of flowers together.   

Characteristics of Oxalis

Oxalis is an annual plant with several species that are especially popular for their colorful foliage and flowers. It is often called shamrock or “false shamrock” but may also go by the name wood sorrel.

Plants in the Oxalis genus are frequently mistaken for clover due to their similar trifoliate leaf structure. However, in the case of oxalis, the leaflets may be heart-shaped or triangular, rather than round like a clover.  The foliage color can vary from green to reddish-purple and flowers may be white, yellow, pink, or purple depending on the species. One of the most notable features of an oxalis plant is its ability to fold its leaves at night or during overcast weather—a phenomenon known as nyctinasty.

Oxalis may propagate through bulbs or seeds but usually remains more localized than the Trifolium clover species. The plants tend to form a clump and don’t spread by trailing.

Oxalis species are native to various regions around the world where they can be found in temperate and tropical climates. Native habitats often include woodlands, meadows, and grasslands where oxalis thrives in the partial shade provided by taller plants or trees.

Oxalis prefer well-draining soil and benefit from moderate watering—allowing the soil to dry out slightly between waterings. Plants can be grown from seeds or bulbs. If planting bulbs, ensure they are placed at a depth of about two inches. For optimal growth, provide them with indirect sunlight and protect them from extreme temperatures.

While both plants can thrive in similar environments and are often found in lawns or gardens, their growth habits differ. Understanding these differences not only aids in proper identification but also enhances our appreciation for these unique plants within our ecosystems.

Clover Hybrids

In recent years there has been a lot of interest in developing clover and oxalis plants with new and interesting foliage colors. These hybrids are more likely to be used as potted specimen plants grown in containers outdoors, or indoors as a houseplant. An example is the 4 Luck® series, an assortment of Trifolium clover with unique colors and variegation that make an excellent filler for combination planters. Or the ‘Plum Crazy’ oxalis, that is a combination of green and burgundy variegated foliage contrasted by bright yellow flowers.

Water Clover

Water clover (Marsilea quadrifolia) is another plant that looks like clover. In fact, “water clover” is not a clover at all, it’s a water-loving four-leafed fern that is found naturally in wetlands around ponds, lakes, or streams. There are quite a few different species of Marsilea that are native to different regions of the world.  

Because of the rarity of four-leaf clovers and their reputation for being a source of good luck, they do have commercial value. That’s why it’s possible to find water clovers pressed or otherwise preserved and sold as “lucky” four-leaf clovers for use in jewelry or other crafts. Four-leaf clover purists should look for their own lucky shamrocks by searching plantings of Dutch clover or by purchasing them from a reputable source of preserved four-leaf clovers.

To learn more about pressing clovers and other plants and flowers see our article, Drying, Pressing and Preserving Flowers.