Are orchids parasites? True, false, simple facts

Orchids as one of the most resilient plants are often a decoration for our homes. We love them for their bright colors beautiful flowers, and exotic appearance and give them to each other for the holidays. The unique way this epiphyte plant grows leads many to suspect that orchids are parasites.

However, one should not rush to conclusions because this topic is still the subject of discussion in modern botany and a common topic of discussion among amateur flower growers.

In this article, we will highlight the main aspects of the life of this flowering plant and answer the question “are orchids parasites?”

What is a parasite?

Any species is considered a parasite if it:

  • Lives in/on the body of another organism
  • Receives nutrients from the host organism
  • Such a “neighborhood” brings problems to the host organism

There are many examples of parasites that you have no doubt heard of. These are intestinal worms of cattle, fleas, and lice … I note that only the species that fits ALL of the above criteria is considered a parasite.

Are orchids parasites?

Is orchid a parasite or epiphyte? Most orchids are epiphytic plants. Their living substrate is not soil, but tree bark (or barks of another living plant).

However, to date, botany has identified 20,000 species of orchids, among which there are also lithophytes, land plants, and even saprophytes.

Epiphytic orchids

This way of life was formed in epiphytic species of orchids due to the need for direct sunlight, which is so scarce under the trees in the forest.

They only cling to the bark of trees with their roots, without harming them, since orchids do not stick their roots into the tree trunks. These roots perform a mechanical function – support, thanks to which the orchid successfully photosynthesizes being level with the tops of the tree branches and does not depend on the host plant for nutrients.

Interesting fact:

How can orchids even get to such a height? Their seeds are very light and easily rise by the wind to the required height near the living plant.

The function of aerial roots

It is not the only function of these modified roots. Orchid roots are called aerial roots because they can often be seen above the substrate outdoors. Aerial roots absorb nutrients literally from the air, organic debris, and rainwater.

Such orchids love dry roots that have access to air. Never create a waterlogged substrate for them, and do not plant in the ground – aerial roots cannot withstand the severity of the soil.

Based on the previous, epiphyte orchids are definitely not parasitic plants, since they do not harm the host plant. Moreover, some studies claim that epiphyte orchids can enter into a mutualistic relationship with the host plant, protecting against fungal infections.

Other studies call orchids that develop haustoria roots to penetrate deeper into the tree, but this is a long and complicated process.

Do orchids steal nutrients?

Haustoria roots make it possible to obtain sugars and other nutrients by stealing them from the host plant. However, today there is no evidence that such stealing brings tangible damage to adult plants. Therefore, these orchids would rather be called commensals, although some insist that they are semi-parasites.

Terrestrial orchids

However, many species of orchids will happily live in the ground, just like the rest of the houseplants. They do not have modified aerial roots, so their roots absorb water and minerals from the soil and do not protrude. These orchids require regular watering but try not to overwater them.

So, terrestrial orchids are not much different from your indoor plants and do not coexist with other organisms, which excludes them from the number of parasitic plants.

Orchids-saprophytes

The substrate for saprophytic orchids is a dead organism. It sounds unpleasant, however, such organisms are orderlies that quickly and safely dispose of organic residues.

In the case of orchids, everything is simple – if the tree withered, the orchid will continue to live on it. Suppose such an orchid no longer has the ability to receive enough light to sustain itself through photosynthesis. In that case, the orchid solves the problem by breaking down the organic matter in the substrate.

A saprophytic species of orchids cannot be a parasite by definition – it’s hard to harm an already dead organism.

Lithophyte orchids

Stones are the substrate for lithophytes. Lithophytic orchids cling to the stone using it as a support, striving for sunlight. At the same time, such plants can receive additional nutrition due to organic residues that fall into rock cracks.

So, we can say with confidence that these orchids are definitely not parasitic plants, since such a plant does not coexist with a living organism.

Are there parasitic orchids?

So, we figured out that the above types of the existence of these plants cannot be called parasitic orchids. Is there an exception?

One of the genera of orchids – Corallorhiza has an interesting feature. These plants are difficult to identify as orchids at first glance – they rarely have pronounced roots and leaves, which means that they cannot provide themselves with their own food through photosynthesis like other plants. What is their secret?

The genus Corallorhiza

Rare species of the genus Corallorhiza coexist with fungi living on their roots, which provide them with nutrients. However, are orchids parasites of fungi? This is one of the debatable issues of modern botany, to determine the symbiotic relationship between an orchid and a fungus.

Orchids rely on fungi to provide them with nutrients.

It all depends on whether these orchids harm the fungi, or vice versa, and help the fungi in some way. Perhaps the orchid does not affect the fungus at all and is a commensal?

This question is difficult to investigate because Corallorhiza lives only in the wild – it is difficult to simulate the conditions for such a symbiosis in the laboratory. So, it is impossible to argue that this orchid is a parasitic plant.

Conclusion

We hope we were able to help you understand what a parasite is and what are the main criteria for this definition.

Summing up, many orchids cannot be called parasites, despite the fact that they live on other plants. We can certainly say that the indoor epiphyte orchids that you often see are definitely not parasites – it’s air plants.

However, there are exceptions – orchid species that develop haustoria roots and plants of the genus Corallorhiza, which some scientists consider semi-parasitic. At the moment, science lacks experimental data to state this with certainty.

Read also:

Are orchids parasitic or symbiotic?

Orchids are typically considered to be symbiotic plants. They have a unique relationship with mycorrhizal fungi, which provide them with essential nutrients such as nitrogen and phosphorus. In return, orchids provide the fungi with carbohydrates produced through photosynthesis.

Is orchid an example of parasitism?

Some orchids are examples of parasitism as they can obtain nutrients from other plants through their roots. However, most orchids are considered to be symbiotic plants, as they have a mutually beneficial relationship with mycorrhizal fungi.

What kind of organism is an orchid?

An orchid is a type of flowering plant that belongs to the family Orchidaceae. It is a eukaryotic organism, meaning it has cells with nuclei and other membrane-bound organelles. Orchids are notable for their beautiful and often elaborate flowers, which come in a wide variety of colors, shapes, and sizes.

What are 5 examples of parasitic plants?

Dodder, witchweed, mistletoe, Indian pipe, and toothwort are all examples of parasitic plants. They attach themselves to other plants to obtain water and nutrients.

Why do people say orchids are parasites?



People may refer to orchids as parasites because some orchid species are partially or fully parasitic, meaning they obtain nutrients from other plants through their roots. However, most orchids are considered to be symbiotic, as they have a mutually beneficial relationship with mycorrhizal fungi. The fungi provide orchids with essential nutrients, while orchids provide the fungi with carbohydrates produced through photosynthesis.

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