Taraxacum is a large genus of flowering plants in the family Asteraceae which includes species typically referred to as dandelion. They are native to Eurasia and North America, however the two commonplace species worldwide, T. officinale and T. erythrospermum, were imports from Europe that now propagate as wildflowers. Both types are edible in their entirety.
The typical name dandelion (dan-di-ly-ən, from French dent-de-lion, indicating “lion’s tooth”) is offered to members of the genus. Like other members of the Asteraceae family, they have very small flowers gathered together into a composite flower head.
Each single flower in a head is called a floret. Many Taraxacum types produce seeds asexually by apomixis, where the seeds are produced without pollination, leading to offspring that are genetically identical to the parent plant.
The types of Taraxacum are tap-rooted, seasonal, herbaceous plants, belonging to temperate areas of the Northern Hemisphere. The genus consists of numerous species which normally (or when it comes to triploids, obligately) reproduce by apomixis, leading to many local populations and endemism. In the British Isles alone, 234 microspecies are recognised in 9 loosely specified areas, which 40 are “most likely endemic”.
In basic, the leaves are 5– 25 cm long or longer, simple, lobed, and form a basal rosette above the central taproot. The flower heads are yellow to orange coloured, and are open in the daytime, but closed at night. The heads are borne singly on a hollow stem (scape) that is typically leafless and increases 1– 10 cm or more above the leaves. Stems and leaves radiate a white, milky latex when broken. A rosette might produce numerous blooming stems at a time.
The flower heads are 2– 5 cm in size and consist completely of ray florets. The flower heads mature into round seed heads called blowballsor clocks (in both British and American English) containing many single-seeded fruits called achenes. Each achene is connected to a pappus of fine hairs, which make it possible for wind-aided dispersal over long distances.
The flower head is surrounded by bracts (often erroneously called sepals) in two series. The inner bracts are erect up until the seeds mature, then flex down to enable the seeds to distribute.
The outer bracts are often reflexed downward, however remain appressed in plants of the sections Palustria and Spectabilia. Some types drop the parachute from the achenes; the hair-like parachutes are called pappus, and they are customized sepals. In between the pappus and the achene is a stalk called a beak, which lengthens as the fruit develops. The beak breaks off from the achene quite quickly, separating the seed from the parachute.
A number of species of Taraxacum are seed-dispersed ruderals that quickly colonize disrupted soil, especially the typical dandelion (T. officinale), which has actually been introduced over much of the temperate world. After blooming is ended up, the dandelion flower head dries out for a day or 2. The dried petals and endurances drop off, the bracts reflex (curve in reverse), and the parachute ball opens into a complete sphere.
Numerous comparable plants in the Asteraceae family with yellow flowers are sometimes called false dandelions. Dandelions are very much like catsears (Hypochaeris). Both plants bring similar flowers, which form into windborne seeds. Nevertheless, dandelion flowers are borne singly on unbranched, hairless and leafless, hollow stems, while catsear blooming stems are branched, solid, and bring bracts. Both plants have a basal rosette of leaves and a central taproot. Nevertheless, the leaves of dandelions are smooth or glabrous, whereas those of catsears are coarsely hairy.
Early-flowering dandelions might be differentiated from coltsfoot (Tussilago farfara) by their basal rosette of leaves, their absence of disc florets, and the absence of scales on the flowering stem.
Other plants with ostensibly similar flowers include hawkweeds (Hieracium) and hawksbeards (Crepis). These are easily identified by branched flowering stems, which are generally hairy and bear leaves.