#Interesting #Facts #Didnt #Roots
1. Not all plants have roots
Roots are absolutely necessary for most plants. They provide the plants with water and nutrients and keep them in place. They can store resources needed to survive a winter or drought, and can help some plants spread and reproduce by releasing new clones nearby. However, some plants have evolved to survive without roots.
A great example is the corpse tillandsia, also known as Spanish moss (Tillandsia usneoides). These are gray-green, intertwined chains of leaves and stems that grow on some trees in parts of America. The plant it draws moisture from the air and, despite its name, is not technically a moss—it’s a plant in the same family as the pineapple, and its relatives have roots, though they’re often few and far between.
The dead tillandsia eventually lost its roots due to its lifestyle, but never developed into true moss. Mosses belong to a group called bryophytes, and they all have no roots and absorb water through their leaves.
2. Feels the world
Roots, like other plant parts, have a keen sense of the world around them – they grow towards moisture and gravity, and away from light. But surprisingly, many details of how they do it remain a mystery.
The sense of gravity is particularly intriguing. Roots are thought to do this using statocytes, specialized cells that contain statoliths, special structures for storing starch. Due to their own weight, the starch granules inside these statoliths sink under the influence of gravity, and the statocytes can somehow determine which direction their internal statoliths are moving.
How they do this, and how it prompts roots to grow toward gravity, appears to be related to the hormone auxin, but we don’t fully understand it yet – although experiments in the microgravity of the International Space Station are helping.
3. Need help from friends
New Scientist space expert Leah Crane recently published an interesting article about all the unexpected reasons why growing plants in space is difficult. One problem is the substrate—lunar dust and Martian soil are toxic and nutrient-poor.
But one team has managed to grow chickpeas in lunar soil – with the addition of earthworms that provide nutrients and fungi that remove toxins. This achievement highlights the importance of the so-called rhizosphere, the soil zone that surrounds plant roots and is directly affected by plant roots.
The rhizosphere is home to many “good” and “bad” microorganisms. Disease-causing species of fungi, bacteria, and small nematode worms can live here—as well as bacteria that help promote growth, provide nutrients, and kill pathogens.
Symbiotic fungi – the so-called mycorrhizal fungi – help plant roots penetrate deeper into the soil and better absorb nutrients, especially phosphorus.
This hidden microbial ecosystem is ignored by many gardeners and farmers—conventional tillage practices disrupt and suppress the root microbiome, making plants dependent on us.
4. Strong and flexible
It may not seem surprising that roots are strong – they are what support huge trees – but their strength can be seen even in humbler plants.
For example, a pore is pulled into the ground by roots that contract, causing the pore to slide down until the roots detect a small enough amount of blue light.
Meanwhile, horseradish roots are known to be very strong, grow quickly and deeply. Once horseradish roots become established in an area, they can become invasive and very difficult to eradicate, as they constantly regenerate from deeply preserved root fragments. For this reason, gardeners are advised to grow horseradish separately, in pots – but even then, horseradish roots can poke through the bottom and penetrate the garden soil.
5. Need oxygen
Despite the fact that the roots are connected to the stems and leaves above the ground, they need a separate local source of oxygen. Water and sugar are transported throughout the plant, but oxygen is not, so without it the roots cannot breathe and function.
It would be a mistake to think that the role of the roots is quite passive – water and nutrients enter them and simply travel up through the plant. However, this is not the case with vital mineral ions, which must be actively pumped from the soil to the plant by root hair cells. This process uses special proteins and energy – and to release it, the root hair cells need oxygen.
Therefore, this is one of the reasons why waterlogged soil can be disastrous for plants
6. Allows you to “walk”
We have many expressions related to roots, from talking about where we came from (“getting back to our roots”) to talking about making a home (“putting down roots”). Often these metaphors are based on the function of roots to hold a plant in place, but there is a known example where roots have the opposite function – allowing the plant to move, as if walking.
Walking palm tree Socrates exorrhiza famous for growing new roots from its trunk. Over time, these roots grow higher and higher, and the old roots may decay or rot. If for some reason the trunk tilts—toward the light or otherwise—the gradual death and growth of the roots can cause the entire palm tree to move away from where it originally sprouted—and to stand up fully stretched again. It is believed that these palms can “walk” about a meter a year in this way.
However, it should be noted that the “roots” of walking palms are not technically true roots – as they grow from the palm’s stem, not from the original root tissue. Such roots are called lateral roots and are already quite common – corn, rice, bamboo and orchids have them.
7. Some plants mostly exist only as roots
Going back to plants that grow on other plants – or epiphytes – some (such as the aforementioned Spanish moss) have no roots, while others, such as the ghost orchid (Dendrophylax lindenii) – lives most of the time only with roots.
Native to Cuba and southern Florida, this orchid has no leaves and has green roots because it has taken over the photosynthetic task normally performed by leaves. This rare orchid lives as roots that wrap around the trunks of its host trees – but sometimes they flower, releasing sweet-smelling white flowers in the forest’s shadows.
Let’s call it “New Scientist”.
