Anyone who thinks of a plant will have in mind its leaves, its flowers, its fruits. Few people will imagine its roots, because in the vast majority of cases, they remain hidden from prying eyes, as they grow, drilling into the earth, in search of oxygen, water and nutrients with which to keep alive all the photosynthetic machinery that emerges on the substrate.
There is as much variety of roots as there are of plants. There are some that are fibrous and delicate, or there are some that are powerful enough to knock down a building. In general, you could say that it is an underground organ most of the time, because there are also aerial roots, like those seen in butterfly orchids (Phalaenopsis cv.), accustomed to hugging the bark of branches and trunks of other plants much larger than it. In these orchids, even that root performs photosynthesis, just like its leaves, since it acquires that green color provided by chlorophyll, which is the pigment responsible for the miracle of transforming sunlight into energy for the plant. This shows how roots can also perform other functions that were not studied in school.
But not only the butterfly orchid produces aerial roots, but an infinite number of species throughout the planet. Many of them, with the purpose of climbing other supports or other plants, like ivy does (Hedera helix). With its powerful aerial roots it attaches to walls and trunks in the garden, to even cover enormous extensions, as occurs throughout our geography. Those people who enjoy one of Adam’s ribs (Monstera Delicious) at home they also know well what an aerial root of a climbing plant is.
Likewise, other vegetables produce aerial roots to increase the resistance of their branches to weight. In the latter case, you should look at the enormous ficus (Ficus spp.), which generate these hanging roots from their horizontal branches. Those roots function as true crutches, allowing these gigantic trees to increase their crown to diameters impossible for other species. For this reason, there have been problems with branch breakage in those ficuses that have not been allowed to develop these aerial roots. Fortunately, the problem has been taken into account, and the solution—once again—has been as simple as listening to nature, leaving and promoting the development of these crutches made by the tree itself. By the way, we must not forget those aesthetic roots of the ficus that grow between and on the Buddhist temples of Cambodia, one of the most recognizable images of the roots of these plant monsters.
You have to imagine the enormous roots that large trees must generate to support the tons of weight of their aerial part. In the giant sequoias (Sequoiadendron giganteum) or these same ficus, the roots function as buttresses, widening at the base to generate a better support point for the plant.
But what is the origin of the root? The answer is in the seed, from which an embryonic root emerges called the radicle. It is the first thing that appears in the seed, which needs many things once it germinates: it longs to settle in a place, to cast anchor, to establish itself and, at the same time, absorb water with which to supply the cotyledons and the first stems and true leaves of the plant. New rootlets will sprout from this radicle, which will increase in size in proportion to the growth of the plant on land. Most roots show growth in favor of gravity, that is, positive gravitropism, which is why they dig into the ground. From those roots that penetrate deeper, other secondary roots will emerge, more horizontally, which will also provide stability to the plant.
![A newly germinated radish seed shows its radicle and absorbent hairs.](https://imagenes.elpais.com/resizer/v2/PAUHUEHIEZEHVBD4HSMYWS563U.jpg?auth=38dc0bf824974e05ba1a9fefbb86ea0bc84727dd3b4e224d7dbb45fbbc23b9da&width=414)
In all these processes of active root growth there is nothing random, since the tips of the roots are extremely sensitive to many parameters found in their environment: oxygen, water, mineral salts, carbon dioxide . In general, the roots will grow first towards where there is more oxygen – since the respiratory function is also produced through them – and then where the water is, which is what will dissolve the mineral substances that are in that soil. or substrate. You should think of the roots as a network of pipes underground. When the plant finds a place in the earth that has water, it enhances root growth towards that water reserve, thus ensuring the survival and vigor of the individual.
On the other hand, it is in the roots where scientists discover much of the controversial plant intelligence, with continuous surprises thanks to inventive experiments. In them, plants and their roots find the best way to obtain what they need. It even seems that the roots would be able to “listen” to the water, directing their growth towards the liquid. Not to mention the symbiosis of plant roots with other organisms such as mycorrhizal fungi or atmospheric nitrogen-fixing bacteria; But that is another issue…
![White, fibrous roots of various parsley plants.](https://imagenes.elpais.com/resizer/v2/4BPWLCYO4RCTZMJOU2HOYWFEBU.jpg?auth=5107cc0b639816ec5ee660f4df84647ac30c550c6093a1f7666707d6f6533f07&width=414)
The roots are also involved in many other processes, such as the production of plant hormones that regulate the growth of the aerial part, hormones that will favor those branches and leaves that produce more energy, just as a good worker in a company should be careful with more pampering Likewise, the roots also accumulate reserve substances, concentrating carbohydrates—“sugars”—to be used when required.
Another adaptation of certain roots is to almost hide a plant in compromised situations, as do various cacti, such as those included within the genus Ariocarpus or the famous peyote (Lophophora williamsii). Its contractile roots decrease in length when severe episodes of drought and high temperatures occur, something common for these exceptional plants. The result will be that the entire body of the cactus will be practically buried, at a lower level of the surrounding soil, which will act by shading the stem of the plants. A spectacular strategy to avoid lethal surface temperatures.
![Peyote has a powerful contractile root that can almost hide the plant in unfavorable times.](https://imagenes.elpais.com/resizer/v2/JKPSLN5MFZHULDI2YJ4FG75JZU.jpg?auth=8773fd3f358031aae709da31c442db4a92d7e88dc0c80a227bb8226c7f7b84cc&width=414)
And, since the plant kingdom is endless, there are also plants without roots and that do without them, as do tilandsias or air carnations (Tillandsia spp.), which absorb water and nutrients through specialized structures on the surface of their leaves, the trichomes.
The roots of plants, those great forgotten ones, are one of the most fascinating parts of vegetables. Many mysteries still remain to be revealed, and much care must be given to the roots of cultivated plants, if we want to have a healthy vegetable that gives joy to those who care for it.
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