Species Profile: Dandelion (Taraxacum officinale)

A field covered in its delicate yellow blossoms is a most uplifting sight and a sure sign that winter is over: The common dandelion, Taraxacum officinale, is one of the most common wildflowers, not only in Ireland but around the world. While this plant with its immediately recognisable flower and characteristic seed head is considered a weed by many today, in the past the dent de leon, the lion’s tooth, was a children’s toy, food, medicine and welcome and respected by all.

Dandelions evolved during the Pliocene in Eurasia. The oldest known evidence of a dandelion is a fossilised seed of Taraxacum tanaiticum, a close relative of today’s common dandelion, which was found in Russia and dated to be some 30 million years old. Later the plant found its way into the writings of the ancient Egyptians, Greeks, Romans and Chinese, where the dandelion was described as a stable food and medicinal plant. Closer to the present children used the white fluid that can be found inside the flower stems and which is a form of latex to paint on pavements, the stems itself were made into bracelets or used to blow a raspberry. The seed heads of the dandelion, known as the dandelion clock, were used to tell the time, although the accuracy of the method is debatable. Each blow was counted as an hour, counting started at 1pm, and the number of blows that were needed to clear the head of all seeds was then declared the current hour. All this was done despite the dandelion’s reputation that even touching it would cause bed wetting. This tale is reflected in many local names like pisterbed in Co. Longford or piss-in-the-bedsin Co. Offaly. In the 20th century scientific studies confirmed that the dandelion is indeed a diuretic with positive effects on urinary tract infections, oedema and high blood pressure. Unlike other diuretics dandelion contains high levels of potassium and naturally counteracts the loss of this mineral that comes with increased urine production. In addition the dandelion also contains high levels of Vitamin A, antioxidants and anti-inflammatory agents as well as glycosides that can ease the symptoms of arthritis and gastritis.

All this explains why the dandelion was and to some extend still is used in folk and alternative medicine. The plant was known to cure pretty much anything from a weak heart, kidney stones and obesity to asthma, bronchitis and other chest ailments. To achieve the required effect the leaves of the plant were eaten raw or boiled into a tea. Sandwiches made of bread, butter and dandelion leaves were meant to cure both indigestion and tuberculosis. On the west Cork islands an infusion made form the roots was used to cure rheumatism. The latex juice of the stem was also used for a variety of health problems but is probably best known as a cure for warts. This comprehensive medicinal use of the dandelion is reflected in its Latin name: Taraxum is a combination of the Greek word for disorder, taraxos, and the word for remedy, akos. The Irish for dandelion, caisearbhán, focuses more on the culinary features of the plant and means the bitter-footed or bitter-stemmed one.

All parts of the plant are edible. The dandelion leaves, best picked before the flowers appear, can be used as part of a salad. The flowers can be made into wine or cooked into a syrup that has a honey like appearance and taste. The roasted and ground roots are well known as a coffee substitute, a use that has been widely applied during the years of World War 2. The roots are also the source of a magenta dye and are still used today to colour wool.

The root of the dandelion and its seeds are the secret to the plant’s success. Each seed head holds up to 400 seeds, each equipped with its own parachute like gliding device. Depending on the strength of the wind these seeds allow the dandelion to travel far and wide and colonize new ground. Dandelions are among the first plants to take over wasteground and their strong and deep growing root, known as a taproot, is perfectly suited to stabilize first the young plant and in time the ground itself. Many plant species start their life with a taproot. After this initial rooting some develop a fibrous root system, numerous roots of similar sizes, and some plants, like the dandelion, keep their taproot as their main root with only few smaller roots branching off this main root. These taproots are often used as energy storage device and we have been taking advantage of those plants and cultivated them into some of our main food plants like carrots, turnips, beetroot and sugar beet.

The dandelion’s leaf rosette appears usually around February and the flowers, which close during the night, follow from March onward. Because the dandelion is one of the first flowering plants it is a vital food source for insects from bees to butterflies. Despite its importance for insects however the dandelion itself doesn’t need any insect’s help reproduce. Dandelions can produce seeds without cross fertilization by a process known as apomixis. All dandelion flowers have both male and female reproductive organs and can produce seeds even without the flower ever opening. This is another reason for the dandelion’s success but also means that most dandelions are clones.

In Ireland around 70 microspecies of the dandelion are known, worldwide there are around 200, although the opinions of botanists differ where one microspecies ends and another one begins. A rare and beautiful representative of these subspecies is the turlough dandelion or marsh dandelion, Taraxacum Palustre, that can only be found around the lakes and turloughs of the eastern Burren in Co. Clare and Co. Galway.

Although the dandelion in general is by no means under threat, there is no real reason to see this beautiful plant with its intricate flowers and seed heads as a weed and declare chemical warfare. Especially right now with insect populations, including bees and bumblebees which are vital to our own survival, plummeting, it is a good idea to let dandelions take over roadsides, parks and gardens.

Carsten Krieger, February 2020