Oro ed argento,
crisoberillo, ambra ed avorio. La margherita.

Grazie all'ottimo Etymonline apprendiamo che la cosiddetta «margherita gialla», quella tutta d'oro, il tarassaco, il piscialletto, il soffione e - in poche parole - il dente di leone, conserva quasi ovunque e da lunga pezza inalterate tutte queste denominazioni.
Dandelion, infatti, proviene da un earlier dent-de-lioun (XIV secolo), from middle french dent de lion, literally "lion's tooth" (from its toothed leaves) ed è translation of medieval latin dens leonis. Other folk names, like tell-time refer to the custom of telling the time by blowing the white seed (the number of puffs required to blow them all off supposedly being the number of the hour), or to the plant's more authentic diuretic qualities, preserved in middle english piss-a-bed and french pissenlit.
Taraxacum - ci informa la Wikipedia (in italiano) - deriva invece dal persiano talkh chakok, che significa "erba amara". Secondo altre etimologie il nome potrebbe derivare dal verbo greco tarasso ("guarisco"), in riferimento alle molteplici proprietà dei succhi lattiginosi dei rizomi di queste piante. Il nome specifico obovatum è dovuto alle foglie a forma di uovo rovesciato, ossia col vertice più largo della base.
Più dettagliata, la Wikipedia in inglese segnala che the persian scientist al-Razi, around 900, wrote "the tarashaquq is like chicory" e che the persian scientist and philosopher ibn Sina, around 1000, wrote a book chapter on taraxacum. Gherardo da Cremona, in translating arabic to latin around 1170, spelled it tarasacon. [...] The plant is also known as blowball, cankerwort, doon-head-clock, witch's gowan, 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 name «dandelion» is a cognate of the names in many other european languages, such as the welsh dant y llew, italian dente di leone, catalan dent de lleó, spanish diente de león, portuguese dente-de-leão, norwegian løvetann, danish løvetand and german löwenzahn.
In modern french, the plant is named pissenlit (or vernacular pisse au lit). Piss-a-bed is an english folk-name for this plant, as are piscialletto in italian, pixallits in catalan and meacamas in spanish. These names refer to the strong diuretic effect of the plant's roots, either roasted or raw. In various north-eastern italian dialects, the plant is known as pisacan ("dog pisses"), because they are found at the side of pavements.
In France, it is also known as laitue de chien ("dog's lettuce"), salade de taupe ("mole's salad"), florin d'or ("golden florin"), cochet ("cockerel"), fausse chicorée ("false chicory"), couronne de moine ("monk's crown"), baraban.
In several european languages, the plant, or at least its parachute ball stage, is named, after the popular children's pastime of blowing the parachutes off the stalk, pusteblume (german for "blowing flower"), soffione (italian for "blowing"), dmuchawiec (polish, derived from the verb "blow") [...]. In other languages, the plant is named after the white latex found in its stem, e.g. mlecz (derived from the polish word for "milk"), mælkebøtte (danish for "milk pot"), kutyatej (hungarian for "dog milk"). The lithuanian name kiaulpiene can be translated as "sow milk". Similarly, in latvian it is called pienene, derived from piens ('milk'), as in catalan is used lletsó (derived from the word llet that means "milk").
The alternative hungarian name gyermekláncfu ("child's chain grass") refers to the habit of children to pick dandelions, remove the flowers, and make links out of the stems by 'plugging' the narrow top end of the stem into the wider bottom end. In turkish, the dandelion is called karahindiba meaning "black endive or chicory". While the root flesh is white, the outer skin of the root is dark brown or black. In swedish, it is called maskros ('worm rose') after the small insects (thrips) usually present in the flowers. In finnish and estonian, it is called voikukka and võilill, respectively, meaning "butter flower", referring to its buttery colour. Similarly, in croatian, the name of this plant (maslacak) is derived from the noun maslac, meaning butter.
In dutch, it is called paardenbloem, meaning "horse-flower". In chinese, it is called pú gong ying, meaning "flower that grows in public spaces by the riverside". In persian, it is called qasedak, meaning the "small postman", because of a belief that it brings good news. Portuguese children also call them o teu pai é careca ("your dad is bald") due to a game which consisted on blowing on a dandelion; if it was left with no seeds, that would mean the other kid's dad was bald. In greek, its seed (and most often the plant itself) is called kleftis, meaning "thief" because it is very difficult to catch once airborne. In Cyprus, the plant is called pappous, meaning "grandfather" due to the white-coloured seed head resembling the white hair of an older man.
In albanian it is called përkalidhe, prakalidhe, as well as luleshurdha (meaning "deaf plant"), radhiqe or luleradhiqe (from a misconception due to its resemblance to chicory leaf, see radicchio), as well as lakra or lakra të egra (translated as "wild lakra"), a name which generalizes a family of similar green leaf vegetables including as well sorrel, chicory, catsear, scarole and other local indigenous plants.