Leontodon taraxacum

Taraxacum officinale grows from a (generally unbranched) taproot and produces several hollow, leafless flower stems, typically 5–40 centimetres (2–15+3⁄4 inches) tall, but occasionally reaching up to 70 cm (28 in) tall. The stems can be tinted purplish, are upright or lax, and produce flower heads that are held as tall or taller than the foliage. The foliage may be upright-growing or horizontally spreading; the leaves have petioles that are either unwinged or narrowly winged. The stems can be glabrous or sparsely covered with short hairs. Plants have milky latex, and the leaves are all basal; each flowering stem lacks bracts and has one single flower head. The yellow flower heads lack receptacle bracts, and all the flowers, which are called florets, are ligulate and bisexual. In many lineages, the seeds are mostly produced by apomixis, even though the flowers are frequently visited by diverse insects. The leaves are 5–45 cm (2–17+3⁄4 in) long and 1–10 cm (1⁄2–4 in) wide, and they are oblanceolate, oblong, or obovate in shape, with the bases gradually narrowing to the petiole. The leaf margins are typically shallowly lobed to deeply lobed and often lacerate or toothed with sharp or dull teeth. The calyculi (the cuplike bracts that hold the florets) are composed of 12 to 18 segments; each segment is reflexed and sometimes glaucous. …

Taraxacum officinale is native to Europe and Asia, and was originally imported to America as a food crop. It is now naturalised throughout North America (including all 50 states of the US and most Canadian provinces), southern Africa, South America, New Zealand, Australia, and India. The plant grows in temperate regions of the world in lawns, on roadsides, disturbed banks, shores of waterways, and other areas with moist soils. They are very hardy plants, able to grow in a variety of environments, and are tolerant of crowding, extremes of temperature, and low moisture. The plant is coveted by collectors in regions where the plant is trickier to grow such as the tropics, where people would often resort to smuggling seeds from overseas.

Conservation. Taraxacum officinale was evaluated in 2013 by the IUCN as "Least Concern" due to a large and stable population. It was similarly evaluated by NatureServe in 2016 as "Globally Secure", G5.

It is considered a noxious weed in some jurisdictions, and is considered to be a nuisance in residential and recreational lawns in North America. It is also an important weed in agriculture and causes significant economic damage because of its infestation in many crops worldwide. T. officinale can serve as an indicator plant for soil potassium and calcium, as the plant favours soils with relatively low concentrations of calcium, but favours soils with relatively high concentrations of potassium. The dandelion is a common colonist of disturbed habitats, both from wind blown seeds and seed germination from the seed bank. The seeds remain viable in the seed bank for many years, with one study showing germination after nine years. This species is a somewhat prolific seed producer, with 54 to 172 seeds produced per head, and a single plant can produce more than 5,000 seeds a year. It is estimated that more than 97,000,000 seeds/hectare could be produced yearly by a dense stand of dandelions. When released, the seeds can be spread by the wind up to several hundred meters from their source. The seeds are also a common contaminant in crop and forage seeds. The plants are adaptable to most soils and the seeds are not dependent on cold temperatures before they will germinate but they need to be within the top 2.5 cm (1 in) of soil. …

The plant has several culinary uses: the flowers are used to make dandelion wine, the greens are used in salads, the roots have been used to make a coffee substitute (when baked and ground into powder) and the plant was used by Native Americans as a food and medicine. Dandelions are harvested from the wild or grown on a small scale as a leaf vegetable. The leaves (called dandelion greens) can be eaten cooked or raw in various forms, such as in soup or salad. They are probably closest in character to mustard greens. Usually the young leaves and unopened buds are eaten raw in salads, while older leaves are cooked. Raw leaves have a slightly bitter taste. Dandelion salad is often accompanied with hard-boiled eggs. The leaves are high in vitamins A and C, as well as iron, phosphorus, and potassium. Dandelion flowers can be used to make dandelion wine, for which there are many recipes. Most of these are more accurately described as "dandelion-flavoured wine", as some other sort of fermented juice or extract serves as the main ingredient. It has also been used in a saison ale called Pissenlit (the French word for dandelion, literally meaning "wet the bed") made by Brasserie Fantôme in Belgium. Dandelion and burdock is a soft drink that has long been popular in the United Kingdom. Another recipe using the plant is dandelion flower jam. …

Dandelion has been used in traditional medicine in Europe, North America, and China.

The Latin name Taraxacum derives from the Arabic tarakhshaqūn, meaning "bitter herb". The Arabic term is possibly of Persian origin. Persian polymath Al-Razi used the word tarakhshaqūn in relation to dandelions, chicory, and endives. Al-Razi wrote "the tarakhshaqūn is like chicory, but more efficacious"; it is unclear exactly to which plant Al-Razi referred however. If Persian in origin, the word could have originally meant "bitter purslane" from تلک (talk or bitter) and چکش (chakūk or purslane). Gerard of Cremona, in translating Arabic to Latin around 1170, spelled it tarasacon. The Latin specific epithet officinale refers to the Latin word for 'medicinal' or 'of the apothecaries'. T. officinale has many English common names (some of which are no longer in use), lion's-tooth, cankerwort, milk-witch, yellow-gowan, Irish daisy, monks-head, priest's-crown and puff-ball; other common names include, faceclock, pee-a-bed, wet-a-bed, swine's snout, white endive, and wild endive. The balls of seed heads are called "clocks" in both British and American English or "blowballs". The common name dandelion comes from the French dent de lion, or "lion's tooth", in reference to the plant's jagged-edged leaves. "Pee-a-bed" and "wet-a-bed" reflect the modern French term for the plant, pissenlit. …