In two weeks of early spring sunshine, Ireland’s first dandelion flowers tracked the sun tirelessly all day, as if in special celebration of their new environmental honour. Reprieved from the mower, many roadsides across these islands have been freshly edged with gold.
Even in America, where pristine front lawns are a badge of belonging, a new “green” movement, No-Mow-May, let dandelions rise in March to give imperilled bumblebees an early draught of nectar.
The New York Times, reporting this new enthusiasm among urban communities in Wisconsin, added a small, ironic consequence. A resident who had left her lawn to grow in some disregard of her neighbours was woken from a nap by policemen at the door. “They were here to ensure I wasn’t dead.”
The fecundity of dandelions is a frequent prompt of prejudice: just one can make so many. In early unreconstructed husbandry, I once gave our small daughter a box of matches and pledged a penny a time for incineration of the shimmering, global seed-heads. She knocked off early and penniless, her fingertips singed.
It takes a couple of weeks in bloom for the dandelion flower head to close around the fibrous spike that later expands into the lacy sphere of the seed-head. Each of the blossom’s florets nurtures one of the 150-200 seeds, poised for flight in the wind. A single plant, flowering in succession, can launch some 2,000 in a season.
How far they fly, each on its separate parasol of branching filaments called the pappus, is still a focus of inquiry.
A 2003 study at the German University of Regensberg found that 99 per cent of seeds land within 10m of their parent. The plant grows about 30cm high, so the seeds’ flight is theoretically brief. The density of dandelions on road verges owes much to the downdraughts gusting from passing traffic.
More recent research, published in Nature in 2018, explored the physics of the seed-head aeronautics. It found in some cases a flight mechanism “highly effective, enabling seed dispersal over formidable distances”. On warm, dry days with thermal updraughts, indeed, some seeds may travel more than a kilometre.
The research, at the University of Edinburgh, used a wind tunnel, adding smoke into the wind and laser photography, the better to see how air moved around the seeds. It discovered a new kind of vortex ring, like a stable air bubble, produced by the feathery structure of the plume. This travels above the pappus, like a parachute, and provides a buoyant drag on the seed’s descent in one more refinement of the plant’s exquisite engineering.
For a botanist, one dandelion plant is not, necessarily, the same as others: the family of Taraxacum officinalis is huge and full of microspecies. Nearly all of them set seed, without cross-pollination and fertilisation, and so never interbreed – a form of asexual reproduction called apomixis.
‘Quite mad’
The Botanical Society of Britain and Ireland (BSBI) has found some 250 microspecies so far. That includes about 70 in Co Dublin alone, but records from some counties are almost totally lacking.
“Ireland very under-recorded so little use,” tersely notes the BSBI database, while a recent workshop granted that anyone devoted solely to dandelions risks being thought “quite mad”.
The microspecies vary between wet and dry habitats, have different shades of pink in their ribs and stalks, and different spots on their leaves. They also have different shapes to the toothy lobes that prompted dents-de-lion (teeth of the lion) that gave the dandelion its name. All these features and more need noting while the plant is in the first flush of flowering.
Another term from the French, pissenlit (pissabed), encapsulates one attribution of the dandelion’s use in folk medicine. But the plant has been involved in remedies for a dozen disorders, from jaundice and heart problems to a stye in the eye. Ireland’s Generous Nature, Peter Wyse Jackson’s exhaustive study of plant uses, also notes that dandelions were considered as an economic herbal crop for the drug trade in the first World War, along with couch grass and foxglove.
In both wars, dandelions found people grinding the root for coffee. Dr Wyse Jackson writes of preparing “delicious” coffee by chopping up the root, slow drying it in the oven for an hour or two, then using a teaspoon of ground root in half a pint of water, simmered for five minutes. One online supplier speaks of the coffee’s “fab smoky, nutty flavour”, an endorsement worthy of any keen barista.
