Have you ever wondered how the blows do or rather the tarassaco flowers to grow even in the asphalt? Seeing them insinuating themselves among the cracks of the concrete rips smiles and seem almost to want to mark a point for nature vs the gray of the cities. But how does this “herbaccaccio” do to survive even in such impervious conditions?
Although the cement is designed to be a resistant and durable material, over time it begins to show signs of failure. The temperature variations make it expand and narrow, the rain alters its structure, and continuous traffic generates small cracks. The asphalt then tends to deteriorate even more quickly. In many cases, these surfaces are only pierced rather than replaced, leaving weaknesses ideal for roasting plants.
And it is precisely in these tiny imperfections that the dandelion He manages to insert himself. Unlike many other plants, which require large cracks, the Leo tooth is able to exploit even the most microscopic cracks in the urban soil.
The seeds of this plant, equipped with a structure similar to a small parachute, move thanks to the wind, Planan light in the air and manage to be honest between the sidewalk slabs or in the chapped asphalt. Their pointed shape, similar to a dart, is equipped with very thin thorns that allow the seed to cling firmly even in the most narrow spaces.
But it is not just luck: each plant can produce up to 20,000 seedsexponentially increasing the possibilities of roaming. Furthermore, Leo’s teeth do not require large quantities of earth and once rooted, they are extremely difficult to eliminate. Their life cycle is surprisingly rapid: a few weeks are enough to go from the seed to the flower.
Robust roots and internal pressure
Once stuck in a crack, the seed begins to sprout. A little humidity and some grain of dust is enough to start the process. The root that emerges is one quetch rootsimilar to that of carrots or beets, capable of sinking vertically into the ground with force and constancy. This root acts like a wedge, looking for water and space while exerting pressure on the walls of the crack.
The real force lies in the turgor pressurea phenomenon that takes place inside plant cells. Radice cells absorb water, generating internal pressure called hydrostatic pressure. It is as if thousands of tiny balloons swell simultaneously, pushing in every direction. In restricted spaces such as cracks in concrete, this pressure focuses on the weakest point, gradually amplifying its fracture.
To give an idea of the force involved: this pressure can reach 0.6 MPAmore than three times that of a car tire. Even if the process is slow, it is inexorable. The root insinuates itself more and deeper, widening the crack to make the plant visible on the surface visible.
Leo’s teeth resist heat, drought, crushing and even being mowed: if you cut the aerial part, The plant regrets the quet. A strategy that makes it almost indestructible in an urban environment.
Leo’s teeth are only the best known of the “green invaders” of the cities. Plants such as Annual Fienarola, Plantain, Musk and Famigured Japanese fallopia (one of the most destructive invasive species in the world) manage to penetrate and fracture concrete – in some cases up to 7.5 cm thick.
Mushrooms can also surprise: some species are able to lift flooring slabs in a few days. And of course, the trees also participate in this slow but inexorable battle, with roots capable of compromising entire sections of sidewalk within a few years.
Between urban damage and biodiversity
Although fascinating to observe, the ability of the lion’s tooth to break the cement also involves Costs and problems for cities. Its roots accelerate the degradation of infrastructures, making it a frequent target of herbicides sprayed along the edges of the roads.
However, not everyone considers him an enemy. Many ecologists underline the fundamental role of these plants in keeping urban biodiversity alive. In particular, they provide nourishment to Bees and other pollinators In an environment poor in floral resources, especially in early spring.
As he explains Philip Donkersleyentomologist at Lancaster University:
Leo’s teeth are an abundant source of nectar and pollen for bees in environments where food diversity is decreasing. They grow with very little land, bloom from early spring to almost the winter and offer food all year round.
In the city like London And Pariscampaigns were born for the protection of spontaneous plants. Signs next to Leone’s teeth recite: “”.
In the end, the lion’s tooth can be considered a annoyance or a natural wonderbut one thing is certain: it embodies the extraordinary ability of the nature of infiltrating even the most artificial environments. A resilience lesson that blossoms just under our feet.
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