It may be that the Dandelion you see most often is Taraxacum officinale, the Common Dandelion, however there are more than 230 species of Dandelion in the UK and the differences between them are small and very complex.
It is not possible to identify a Dandelion to species from a single photograph. Many different things have to be taken into account.
The character of the leaves for instance. Some species have alternate lobes and some are opposite and there are some species that don’t have lobes at all, some have a purple central rib and in some it is pale.
So can we even tell that it is a Dandelion?
Yes of course we can. Dandelions belong to the Asteraceae (Daisy) family and they have quite distinctive characteristics.
Like other members of the Asteraceae they have a composite flower head made up of many smaller flowers.
This next picture is of a Common Daisy (Bellis perennis) and shows the arrangement of central disc florets (yellow) and the outer ray florets (white), each “petal” and “disc” is a complete flower in itself and together they make the flower head that we call a Daisy.
The other easy to spot and important characteristic is that unlike other lookalikes there are no leaves on the flower stem and it is unbranched, each flower head is carried on a single, bare stem. that will rule out the Hawksbits and other pretenders like Cat’s-ears.
Dandelions secrete latex, not very much in the wild varieties but scientists have developed cultivars for the production of rubber and there are tests being carried out today with tyres made of Dandelion rubber.
At the base of each flower there are a series of down turned bracts. These are sometimes mistaken for sepals but remember that this is a flower head and not an individual flower, each ray floret has it’s own sepals at the base which will eventually become the parachute that will carry the seed.
Each “petal” is a whole flower. It has all that is required to make a flower, a corolla (fused petals) male reproductive parts and female parts too and an ovary that will become a seed.
I have to do a drawing to show you how this works. The anthers develop first and they produce pollen on the inside, The style grows through the middle of the anthers and collects the pollen. The style has two receptive surfaces that are pressed closely together, the pollen collected on the outside does not affect them. So the style carries the pollen.
With 230 plus species in the UK you can pretty well find Dandelions in flower at any time of year, they don’t all flower at the same time, however there is a season.
April is the best time to look for Dandelions, the fields are full of them.
The seeds are called achenes and the parachute is called a pappus and the parachute is actually made from modified sepals of the tiny flower called a ray floret. Between the seed and the parachute is a stem called a beak. The whole of this structure has grown from the style that both distributed and collected pollen for the flower.
I am not really sure why it hasn’t been modified and cultivated for the garden. Dandelions are a very good weed to have in the garden, they have a very deep tap root that draws nutrients up to the surface and makes them available for other, more fancy, flowers. They also attract pollinators.
If you pick a flower and chase your sister with it then she will scream and run away because if you can successfully touch her with the flower then she will be fated to wet the bed. (Dandelions are a lot of fun)
The common French name for a Dandelion is “Pissenlit” and “lit” is the French word for bed. There is some logic in this, Dandelion root has been used in herbal medicine as a diuretic and it does indeed make you piss en lit.
Our own common name Dandelion is derived from another French name “Dent de Lion,” meaning Lion’s tooth and that is a reference to the shape of the leaf.