Herb
A sun, then a moon, then a wish — the most cheerful invasion in the lawn.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Few plants have been given so many names by people trying to describe the same three things: the toothed leaf (dent de lion), the diuretic effect (the French pissenlit, and the English piss-a-bed that Culpeper cheerfully records), and the clock of seeds. Blowing the seed head to tell the time or count a lover's faithfulness is one of the most widespread children's divinations in Europe.
The plant's cycle is its whole symbolism: a solar yellow flower that closes, transforms and reopens as a silver sphere, then disperses. Practice reads it as sun, moon and stars in one organism, and uses it for wishes, for messages to the dead, and for divination. The root, roasted, was a coffee substitute in both world wars.
It is also an apomict — most dandelions set seed without pollination, so a lawn full of them can be near-identical clones of one plant. The botany is genuinely strange, and rather more interesting than the folklore.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
European children's divination
The seed head is blown to tell the hour, count the years, or settle whether someone loves you. It is the first divination most people in Europe ever perform, learned from other children rather than from any book.
Carried forward
Nicholas Culpeper, The Complete Herbal (1653)
Culpeper notes that it is vulgarly called piss-a-beds, gives it to Jupiter, and observes that it opens obstructions of the liver — a claim he makes about a great many plants and never once qualifies.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.