Most dandelions reproduce without sex, cloning themselves into thousands of microspecies
Many dandelions set seed with no pollination at all, producing offspring genetically identical to the parent. Every distinct clone can count as its own microspecies, which is why Britain and Ireland alone list about 235 of them and botanists worldwide now recognise roughly 2,800.
The genus name comes from an Arabic word for bitter herb, possibly of Persian origin; the Persian scholar Al-Razi used it for dandelions, chicory and endives. The English word is French dent de lion, lion's tooth, after the jagged leaves. Folk names run to pee-a-bed, from the leaves' diuretic reputation, and the Swedish maskros, worm rose, after the thrip larvae that often live in the flowers.
Dandelions are thought to have arisen in Eurasia around 30 million years ago, and fossil seeds turn up in Pliocene deposits in Belarus. Egyptians, Greeks and Romans knew the plant, Chinese medicine has used it for over a thousand years, and it may have crossed to North America on the Mayflower. Deliberate cultivation in the United States seems to have started in the mid-19th century, with leafy varieties bred for salad.
Each yellow head is a cluster of tiny florets that ripens into a blowball of seeds, each hanging from a feathery pappus. That parachute creates a vortex ring that stays attached to the seed and carries it far; it can also fold up in damp air, holding seeds back until conditions favour dispersal. Spring seeds weigh about half a milligram, summer ones around 0.3. The roots store the fibre inulin, and the Kazakh dandelion makes rubber.
Wildlife benefits: rabbits, deer, turkeys and many birds eat the leaves and seeds, and early-spring pollinators rely on the nectar when little else is flowering. The same vigour makes the common dandelion a pest. Several Canadian provinces list it as a noxious weed, and Denali National Park in Alaska calls it the park's most common invader, running a yearly Dandelion Demolition to clear roadsides. Specialists in the genus are called taraxacologists.
Source: Taraxacum
